Around the start of each month, MiLB.com staff will break down the state of all 30 organizations with updates on their top prospects, Minor League affiliates and more in a feature called "Farm system storylines."
AL East
Baltimore Orioles
Ryan Mountcastle got off to a slow start in his first taste of Triple-A with an unspiring .194/.257/.258 slash line through nine games for Norfolk. Baltimore's No. 2 prospect quickly made the necessary adjustments and batted .348/.361/.638 in the last 16 games of the month, including eight multi-hit contests. All five of his home runs and 13 RBIs came in that final stretch. Mountcastle started 22 of his 25 games at first base -- the other three coming at third -- while Orioles third baseman Rio Ruiz and first baseman Chris Davis each posted a sub-.650 OPS in April. The case is mounting for Baltimore to give Mountcastle a shot at the Majors soon. -- Chris Tripodi
Boston Red Sox
Jarren Duran made his full-season debut less than two months after he was taken in the seventh round of the 2018 Draft and hit the ground running with Class A Short Season Lowell. He continued to impress with a .367/.396/.477 batting line and 12 stolen bases in 30 games after a promotion to Class A Greenville, and Boston's 10th-ranked prospect has improved even more this season with Class A Advanced Salem, posting a .404/.462/.553 slash line with nine extra-base hits (five doubles, three triples and one homer) and 11 stolen bases in 23 games in the Carolina League. The 70-grade speedster's 37 extra-base hits in 90 Minor League games have been a pleasant surprise after he had just 38 over 168 games in his three-year college career at Long Beach State. -- CT
New York Yankees
Though the surface stats don't pop off the page, Deivi Garcia didn't even last a month in his second stint at Class A Advanced Tampa before earning a promotion to Double-A Trenton. The Yankees' No. 4 prospect had a 3.06 ERA and 1.25 WHIP in 17 2/3 April innings, which pale in comparison to his 1.27 ERA and 0.95 WHIP over 28 1/3 innings in the Florida State League last season, but his 16.8 strikeouts per nine innings represent a huge jump from his 11.1 mark on the circuit last year. The 19-year-old has steadily built up his pitch count in each of his four starts this season and peaked at 93 pitches at Charlotte on April 24, and his progression with the Thunder -- particularly when it comes to his increased walk rate in 2019 -- will be one to watch. -- CT
Tampa Bay Rays
Here's the Lowe-down: Brandon Lowe started the season with the Rays after signing a Major League contract, and Nate Lowe was called up to Tampa on April 29. While Josh Lowe may not join them in the Florida sun any time soon, Nate's younger brother enjoyed a breakout April at Double-A Montgomery. The Rays' No. 15 prospect posted an impressive .260/.370/.519 batting line with four homers, 14 RBIs, 15 runs scored and four stolen bases in 22 games, and the long balls were a surprise after he hit 19 in his first 277 Minor League games. His fly-ball rate climbed over 40 percent at Class A Advanced Charlotte last season with no tangible results, but he's maintained that extra loft in 2019 while hitting the ball harder and driving fewer pitches into the ground, an intriguing combination that could mean his improved power is here to stay. -- CT
Toronto Blue Jays
Vladimir Guerrero Jr. is now a Major Leaguer, but there's still plenty of excitement in the Blue Jays farm system without the wunderkind. Nate Pearson, the team's third-ranked prospect, is a big reason why. An oblique injury and a fractured ulna held him to 1 2/3 innings in 2018, but Pearson has made up for lost time by going 3-0 with a 0.95 ERA, 0.63 WHIP and 30-to-2 strikeout-to-walk ratio over 19 innings in five starts at Class A Advanced Dunedin. The 22-year-old right-hander's 75-grade fastball touched 102 mph in his April 25 start, when he struck out 10 and walked one over five innings in Jupiter, and he's holding Florida State League opponents to a .152 batting average. His next stop is Double-A New Hampshire with a promotion coming officially Friday. -- CT
AL Central
Chicago White Sox
How could this be about anyone other than Luis Robert? The No. 37 overall prospect was arguably the hottest hitter in the Minor Leagues in April, leading the way with a .453 average, .920 slugging percentage and 1.432 OPS through 19 games with Class A Advanced Winston-Salem. He was the only player with at least eight home runs and eight stolen bases across all four levels. The White Sox figured the 21-year-old outfielder had destroyed the Carolina League enough and moved him to Double-A Birmingham on May 1. Robert has dealt with multiple injuries over his three seasons in the White Sox system, but if he can stay healthy and keep this breakout going, he's got multiple above-average tools to make him one of the game's most exciting prospects throughout the summer. -- Sam Dykstra
Cleveland Indians
Cleveland's 25th-ranked prospect, Will Benson put together the best individual offensive performance of the month on April 18 when he had the Minors' first four-homer game since 2014. But the 2016 first-rounder was more than just that game alone. He finished April with a .282/.393/.634 line, six homers, one triple and five doubles over 20 games with Class A Lake County. His 1.027 OPS ranked third in the Midwest League for the month. That's a sizable jump from the left-handed slugger, who finished his first trip with the Captains with a .694 OPS over 123 contests. Benson still struggles to make regular contact -- he struck out in 40.5 percent of his plate appearances in April -- but when he does put the bat on the ball, he's proven to be more capable of doing big damage than he has been in years past. -- SD
Detroit Tigers
Like Robert and the White Sox, no one else could feature in the Tigers' spot other than 2018 top pick Casey Mize. The 22-year-old right-hander bulldozed his way through the Florida State League with a 0.35 ERA, 0.31 WHIP, 25 strikeouts and one walk over four starts with Class A Advanced Lakeland. How did he follow that up? By throwing a no-hitter in his Double-A debut on April 29. Mize has been downright untouchable across the board at the start to his first full season and leads Minor League Baseball in average-against (.064) and WHIP (0.26) and is tied for second with a 0.26 ERA. Mize has the arsenal to back up the gaudy stats with two plus pitches in his fastball and slider and a plus-plus offering in his splitter. It's enough to make anyone wonder how much longer he'll last in the Minors before banging down the door to Detroit. -- SD
Kansas City Royals
Few batters controlled the strike zone at any level of the Minors like Nicky Lopez did in April. In fact, none of the qualified hitters in the Minors topped his 4.0 BB/K ratio or 3 percent strikeout rate through 21 games with Triple-A Omaha. (He walked 12 times and struck out only thrice in 99 plate appearances.) Because Lopez put the ball in play a ton, he was able to take advantage of his above-average speed and hit .346/.436/.494 for the month. It's true there wasn't much power behind the good average and OBP -- only seven of Lopez's 28 hits went for extra bases -- but that type of approach and elite contact rate often translate well to the game's highest level. The Royals' No. 8 prospect is unfortunately stuck behind Whit Merrifield and Adalberto Mondesi at second base and shortstop (the only two positions he's played in 2019), but it's a not a tough bet that he'll see Kansas City at some point soon. -- SD
Minnesota Twins
This was the first time No. 19 Twins prospect Jordan Balazovic has pitched with a Minor League affiliate in April, and he certainly made it count. The 20-year-old right-hander posted a 2.18 ERA and 0.92 WHIP with 33 strikeouts and only four walks in 20 2/3 innings at Class A Cedar Rapids. He didn't allow more than two earned runs in any of his four outings and struck out at least seven batters each time out. His 39.8 percent strikeout rate was sixth-best among 96 qualified Class A pitchers. Taken in the fifth round of the 2016 Draft, Balazovic pitched out of the Gulf Coast League his first two seasons and was held back in extended spring training before making 12 appearances for Cedar Rapids last season. With a low-to-mid-90s fastball and solid slider and changeup, he's got the mix to stick as a starter, and with these results, he could be the next big thing in the system alongside Royce Lewis, Alex Kirilloff and Brusdar Graterol. -- SD
AL West
Houston Astros
When Yordan Alvarez went yard during a four-hit performance on Saturday, he took a share of the Minor League home run lead with his 11 dingers matching the totals of Kevin Cron (D-backs, Triple-A Reno) and Sam Huff (Rangers, Class A Hickory). The round-tripper also gave Alvarez a whopping 29 RBIs through 21 games, and even after an 0-fer the next day, the No. 41 overall prospect still had a .347/.443/.867 slash line. If he continues to mash at even close to this pace, not even Houston's roster depth will be able to keep him down. -- Josh Jackson
Los Angeles Angels
This time last year, Griffin Canning had made his pro debut, shot through the Class A Advanced level in two starts and held his own through three Double-A starts in the matter of less than a month. On Tuesday, he made his first start for the Angels, striking out six over 4 1/3 innings. In between, he went 5-3 with a 3.27 ERA, striking out 142 over 129 1/3 innings across 28 Minor League starts. Three of those starts were for Triple-A Salt Lake in April, when the 22-year-old right-hander allowed two runs -- one earned -- and fanned 17 over 16 innings. Meanwhile, Chris Rodriguez -- another young Halos righty -- missed all of 2018 with a stress reaction in his back but held opponents to a .188 batting average and punched out 13 over 9 1/3 innings across three April starts for Class A Advanced Inland Empire. -- JJ
Oakland Athletics
With Jesus Luzardo, A.J. Puk and James Kaprielian all remaining out of action through the opening month of the campaign, hitters are a natural focal point for fans of the Oakland Minor League system. There's plenty of good news coming out of Triple-A Las Vegas in that department. The Aviators -- not only a new A's affiliate but a team with a new name and new ballpark -- have seen eighth-ranked Jorge Mateo post a .352/.397/.546 slash line, steal seven bases and triple six times in 23 games. Sean Murphy, the system's top position-playing prospect, batted .324/.402/.459 over his first 19 games. Las Vegas scored 192 runs -- second most in the Pacific Coast League -- through 26 games, starting 16-10. -- JJ
Seattle Mariners
Right-hander Justin Dunn and outfielder Jarred Kelenic -- the two high-profile prospects the Mariners acquired from the Mets in the offseason Robinson Cano deal -- have not opened the door for buyer's remorse. The 23-year-old Dunn started the year strong over four starts for Double-A Arkansas, punching out 27 over 18 1/3 innings while managing a 3.44 ERA. The 19-year-old Kelenic led Class A West Virginia in total bases (47), hits (27) and homers through 21 games, posting a .329/.427/.573 line. Meanwhile, 2015 26th-round pick Ljay Newsome is making California League hitters miserable. Repeating the circuit, the 22-year-old right-hander posted a 1.52 ERA (second on the loop to Lake Elsinore's MacKenzie Gore's 1.37) while going 4-1 with a Cal League- and system-best 46 strikeouts over 29 2/3 innings through five starts. -- JJ
Texas Rangers
The aforementioned Sam Huff, with whom Alvarez had a share of the Minors home run lead early in the week, took sole possession with his 12th dinger in 23 games on Tuesday. Huff, who returned to Class A Hickory to open 2019, couldn't make a much stronger case for promotion. On top of the long balls, he's batting .325/.365/.825. Teammate Hans Crouse -- the Rangers' top prospect -- is outclassing the South Atlantic League, too. The 20-year-old right-hander has fanned 23 and walked three over 20 1/3 innings, going 2-0 with a 1.33 ERA across four starts. -- JJ
NL East
Atlanta Braves
The Braves surprised some by sending both Cristian Pache and Drew Waters to Double-A Mississippi to open the season. Both are Top-100 prospects (Pache at No. 33, Waters at No. 81) and capable of playing exceptionally well in center field. It figured that Waters would be back in Class A Advanced Florida, where he played only 30 games last season, so both could get equal chances to roam center. Instead, they're covering a lot of ground on the same grass, and both players have been among the Southern League's most productive hitters early on. Pache finished April ranked second in the Double-A circuit with a .934 OPS, while Waters was sixth at .888. The latter's 111 doubles also topped the Southern League. Pache is receiving the lion's share of starts in center to open the season, but Waters, who is mostly playing in right, also got seven looks there in April. Their partnership should create nothing but good problems for Mississippi and the Braves at large down the line. -- SD
Miami Marlins
The Marlins are in full-rebuild mode but lack the top talent and depth to claim one of the game's best farm systems, meaning they'll need some popup prospects to break out in 2019 if this process is going to work. Zac Gallen could fit the bill nicely. The organization's No. 18 prospect led Pacific Coast League qualifiers with a 0.81 ERA, 0.57 WHIP, .126 average-against and 38 strikeouts over 33 1/3 innings in April. That's even more notable considering how the change to using Major League baseball has Triple-A slugging numbers up in a major way over the season's first month. The 23-year-old right-hander may not have stand-out stuff -- his cutter was his only clear above-average pitch coming into the season -- but his is a deep arsenal and he's got the good command to keep hitters on their toes. With 187 1/3 innings of Triple-A ball under his belt, he should see Miami at some point in the first half. -- SD
New York Mets
It's taken some time, but Mets No. 8 prospect Anthony Kay is starting to look like the 2016 first-rounder that he is. Kay underwent Tommy John surgery soon after being picked 31st overall out of UConn three years ago, meaning it wasn't until last season that he was able to pick up his first full workload in the Minors. Now at Double-A Birmingham, he's doing more than just pitching every fifth day. The 24-year-old left-hander ranked fifth in the Eastern League with a 1.85 ERA and seventh with a 29.3 percent strikeout rate over 24 1/3 innings. On top of the results, he's handled longer assignments as well, hitting the 90-pitch mark in each of his last three starts of the month. With three above-average pitches in his fastball, curve and changeup, Kay has the stuff to start. He just needs to show the durability, and he's well on his way toward that goal. -- SD
Philadelphia Phillies
When the Phillies sent last year's No. 3 overall pick and former Wichita State star Alec Bohm to Class A Lakewood (instead of Class A Advanced like most premium college performers), they must have hoped he would make a statement. That's exactly what the 22-year-old third baseman did, hitting .367/.441/.595 with three homers and a 14/12 K/BB ratio in 22 games in the South Atlantic League. As such, he received his promotion to Clearwater on April 30. What does Bohm's dominance tell us? Not much yet, other than that his pro hitting woes of 2018 -- when he hit .252 with a .659 OPS between the Gulf Coast League and Class A Short Season Williamsport -- are things of the past. Bohm still has above-average potential when it comes to his hit and power tools, but he'll have a better chance to prove it in the FSL, where he'll face fewer questions about his assignment. -- SD
Washington Nationals
Carter Kieboom Day came early in the nation's capital. The Nationals were grooming their top prospect to get some time on the infield at some point in 2019, getting him opportunities at second and short while giving him his first taste of Triple-A in Fresno. Unfortunately, injuries to Trea Turner and Anthony Rendon left Washington light on infield depth in the Majors. Fortunately, Kieboom was hot enough in the PCL to justify the promotion, hitting .379/.506/.636 with 10 extra-base hits and 16 walks in 18 games before getting the call on April 26. His time in The Show has been up and down -- two homers and lots of hard contact but just 3-for-23 (.130) and some rough defense at short -- so it'll be interesting to see how the Nats handle Kieboom again when Turner returns. Don't bet against his bat turning things around before then, though. -- SD
NL Central
Chicago Cubs
Coming off Nico Hoerner's stellar pro debut, the Cubs made the 24th overall pick the only 2018 first-rounder to be assigned to Double-A out of the gate. And Hoerner, who turns 22 on May 13, didn't take long to get comfortable, notching a .293/.388/.483 slash line in 17 games for Tennessee. But that all got halted when the Stanford product was hit by a pitch and landed on the injured list with a bruised wrist. The good news for Cubs fans, though, is that if all goes smoothly, Hoerner should be back on the field in short order. -- Kelsie Heneghan
Cincinnati Reds
With Nick Senzel starting the season on the injured list with an ankle injury, Josh VanMeter stepped up to lead the Triple-A Louisville lineup. Highlighted by a three-homer game, the left-handed hitter topped the International League with 11 April dingers while notching a .358 average to boot. When Senzel got healthy, he joined his roommate on the fun, getting a hit in all seven April games he played in. While rumors swirl that the No. 5 overall prospect will likely head to the Majors this week, the Bats will still have VanMeter to rake -- until it's his time, of course. -- KH
Milwaukee Brewers
This year has already signified a couple big Triple-A debuts in the Brewers system in top prospect Keston Hiura and his San Antonio Missions. The 22-year-old second baseman has handled the transition with ease, drilling seven homers -- already halfway to a career high -- while hitting .318 in 24 games. Following their tenure as a Double-A club, the Missions are also enjoying their ascension into the Pacific Coast League, beating a rehabbing Clayton Kershaw on Opening Night before winning their first two home games of the year in walk-off fashion. -- KH
Pittsburgh Pirates
Triple-A players are always one call from The Show, and in the Pirates system last month, it was mostly top prospects answering the phone. Pittsburgh No. 5 prospect Cole Tucker, Bryan Reynolds (No. 8) and Jason Martin (No. 11) were tapped for their Major League debuts, while Kevin Kramer (No. 6) was recalled for a couple games. Kevin Newman (No. 9) began the season in the NL and should return soon after rehabbing a finger laceration. The pipeline to the Steel City should continue to flow as top prospect Mitch Keller shines on the mound and slugger Will Craig (No. 15) rakes at the plate for the Indians. -- KH
St. Louis Cardinals
In recent years, St. Louis has seen the debuts of several big pitching prospects like Dakota Hudson, Alex Reyes, Jordan Hicks and Jack Flaherty. Now, it looks like the next flock is hatching in the Florida State League as Class A Advanced Palm Beach led all levels of baseball with a 2.06 team ERA in April. Thirteen of the 16 Cardinal pitchers notched a mark below 2.50 with the "worst" ERA coming from starter Edgar Gonzalez and his 3.32 mark. Johan Oviedo, Angel Rondon, Perry DellaValle and Alex Fagalde round out the rotation while Junior Fernandez and Patrick Dayton lead this stingy bullpen. -- KH
NL West
Arizona Diamondbacks
Top D-backs pitching prospect Jon Duplantier started the season in the big league bullpen before returning to Triple-A Reno, where he joined the rotation. His first three PCL outings were terrific. The righty put up a 1.04 ERA and fanned 11 over 8 2/3 innings, limiting opponents to a .111 average. One of his bullpen mates in Arizona was No. 14 D-backs prospect Yoan López, who won't remain a prospect for long, solidifying his spot in the Majors with a 0.77 ERA through his first 15 relief appearances. On the position player side, D-backs prospects are off to slow starts. Arizona's No. 1 Jazz Chisholm sported a batting average of just .151 through his first 20 games with Double-A Jackson, although his .706 OPS made that number a bit more palatable. Same goes for catcher Daulton Varsho, just a .221 hitter but with an .766 OPS through 19 contests for the Generals. -- Tyler Maun
Colorado Rockies
With a rash of injuries at the Major League level in April, the Rockies' prospect depth was tested. No. 10 Colorado prospect Josh Fuentes and No. 14 Yonathan Daza each made their big league debuts and have pitched in with a potent Triple-A Albuquerque offense before and since. The highlight of the Isotopes' start to the year has been top Rockies prospect Brendan Rodgers, who surged toward the end of April, highlighted by a torrid series against Salt Lake. The shortstop went 12-for-22 with two homers, four doubles, a triple and six RBIs. Further down the ladder, last year's Rockies first-round pick, Ryan Rolison, dominated the South Atlantic League to earn a rare April promotion. With Asheville, the lefty went 2-1 with a 0.61 ERA in three starts, striking out 14 in 14 2/3 innings and posting a 0.68 WHIP. He debuted at the Class A Advanced level with six shutout innings for Lancaster opposite No. 2 San Diego prospect MacKenzie Gore. -- TM
Los Angeles Dodgers
Double-A Tulsa boasted one of the Minors' most intriguing and loaded rosters coming into the season and for good reason. Five of Los Angeles' top 10 prospects are on that squad and even less-heralded names have impressed there. Omar Estevez and Cristian Santana, the No. 19 and 26 Dodgers prospects, opened the year scorching at the plate with Estevez batting .385 through his first 20 games and Santana at .329 through 21. Los Angeles' No. 1 Keibert Ruiz and No. 10 DJ Peters have yet to hit their stride at the plate, but No. 3 Gavin Lux boasted a .308 average and .841 OPS through 18 games in his return assignment to the Texas League. The top pitching prospect in the organization has starred for the Drillers, too. Dustin May's ERA sat at 1.50 through five starts with 27 strikeouts against seven walks in 24 innings pitched. Elsewhere in the system, Will Smith has raked for Triple-A Oklahoma City, boasting a .914 OPS in April. -- TM
San Diego Padres
The prospect-packed San Diego system has gotten strong work from two of its top-rated arms with Class A Advanced Lake Elsinore. No. 2 Padres prospect MacKenzie Gore whiffed 27 against three walks in his first 22 innings, going 2-0 with a 1.23 ERA over four starts. Rotation mate Luis Patiño wasn't quite as dominant but still put together a solid month, posting a 4.50 ERA and striking out 18 with 13 free passes in 14 frames while limiting opponents to a .196 average. On top of making an 11-game cameo with San Diego in April, middle infielder Luis Urías has crushed with Triple-A El Paso. Through 12 Pacific Coast League games, Urias owned an eye-popping .364/.435/.891 slash line with seven homers -- he hit just eight all of last year -- including the first three-homer game in Chihuahuas history. First baseman Josh Naylor is putting together one of his best offensive starts, too, batting .305/.393/.590 with seven homers and 22 RBIs in 25 games. -- TM
San Francisco Giants
The biggest storyline out of San Francisco's system to start the year is the injury to top prospect Joey Bart. San Francisco's catcher of the future was hit by a pitch while with Class A Advanced San Jose in mid-April, fracturing his left hand in an injury that is expected to cost him four to six weeks of action. No. 2 prospect Heliot Ramos will also miss a month of his own with San Jose with a knee injury. One of the brightest spots in the Giants system was near the back end of the organization's top 30 prospects. Former San Francisco first-rounder Tyler Beede is discovering himself again for Triple-A Sacramento. The right-hander's ERA sat at 1.99 after five starts, and his command is back on track after a couple of up-and-down seasons, with 34 strikeouts against 10 walks in 22 2/3 innings and a .179 opponents average. -- TM
