Ryan McMahon, Rockies
Jonathan Gray, Colorado's top pick in the 2013 Draft, may be grabbing many of the headlines in and around Denver, but he wasn't the only Rockies selection to stand out in his pro debut this summer.
In addition to the first-round hurler, Colorado's second-round pick Ryan McMahon was a breakout performer. In 59 games with Rookie-level Grand Junction, the third baseman hit .321 with 11 homers and a .984 OPS. McMahon, ranked 17th in the Rockies system, proved a dynamic player in his debut, flashing strong tools at the hot corner while impressing Colorado personnel with his makeup and work ethic.
The left-handed hitter was ranked 78th on Jonathan Mayo's pre-Draft Top 100, with Mayo noting that McMahon was also a standout quarterback at Mater Dei High School in California -- the same school that's churned out stellar QB prospects such as Matt Leinart, Matt Barkley, Colt Brennan and Max Wittek.
Indeed, Grand Junction manager Anthony Sanders thinks McMahon's football past helped in his pro debut. The 18-year-old skipped the complex leagues and went straight to the Pioneer League with stunning success.
"I just think it's his leadership qualities," Sanders said. "A lot of that carries over from his being a high school quarterback. He was not overwhelmed by the competition, stuff like that."
Of course, McMahon's athleticism had plenty to do with his success too. The left-handed hitter is an excellent athlete and possesses what Sanders described as a "natural, sweet swing."
"I think he looks like he'll definitely hit for a high average and he definitely looks like he has some power as well," Sanders said. "He hits the ball with power to all fields. He just needs to get bigger and stronger, which is what you expect of a high school kid when he's just signing."
Sanders is bullish on McMahon's chances to convert his tools into a Major League career, owing in large part to strong makeup and instincts for the game.
"Just the way he was talking on the infield, going out there calling certain plays defensively," Sanders said. "He's talking amongst the infielders, letting them know what to do in certain situations. He has the instincts that we try to teach kids at that age."
Austin Meadows and Reese McGuire, Pirates
The silver lining for the Pirates in 2012 when Mark Appel slipped away unsigned was that they received an extra early pick in the 2013 Draft. That gave Pittsburgh a pair of prime selections in this year's Draft, and the team used them on a pair of toolsy high schoolers in Georgia outfielder Austin Meadows and Washington catcher Reese McGuire.
The teenage duo debuted together in the Gulf Coast League, and thus far, it looks like general manager Neal Huntington and company chose wisely.
Meadows was picked ninth overall, and his performance certainly eased the pain for Pirates fans after Appel was selected first and had a solid debut with Houston. The center fielder was named a GCL All-Star after hitting .294 with a .918 OPS in 43 games, and Pittsburgh promoted their No. 4 prospect to the New York-Penn League at season's end to compete with Jamestown in the playoffs.
After hitting .529 in a five-game sample with the Jammers to end the regular season, the 18-year-old went 4-for-11 in the postseason and hit a key home run to help Jamestown take Game 1 of the New York-Penn League semifinals.
McGuire followed Meadows the whole way. The backstop was also named a GCL All-Star, managing a .780 OPS in 46 games. The Pirates' No. 8 prospect didn't hit any home runs, but knocked 11 doubles and also stole five bases while finishing third in the league with a .330 average.
The results don't show it, but there were trying times for the pair, most of which came on the periphery of actual game action. Near the end of the season, Meadows spoke with MiLB.com about his debut, noting that among his biggest challenges was living away from home for the first time, working a full-time job and living a very different lifestyle.
"Pretty much every day, you have to be as consistent as you can," he said. "The factors outside of baseball, like being away from home, friends, family -- you have to push yourself through the hard times. Especially when you're slumping, there's nobody to go to.
"I had some tough times earlier, but the big thing about professional baseball is there's always another day. It was definitely a good experience down there, and I'm glad it ended well for my first year."
Phillip Ervin, Reds
A number of college hitters found success in their pro debuts with the Cubs' Kris Bryant and Miami's Colin Moran among the first-rounders who hit well out the gates. None of them were quite as dynamic as Cincinnati's Phillip Ervin, though.
The outfielder from Samford University was taken 27th overall in the first round this summer and mashed in the Rookie-level Pioneer League and Class A Midwest League. Between the two, Ervin hit .331 with nine homers, a .989 OPS and 14 stolen bases out of 15 attempts in 46 games.
Ranked fourth in Cincinnati's system, Ervin is also a promising defender in center. The biggest question about the Leroy, Ala., native at Draft time regarded his power. He'll be tested next year at higher levels, but his 21 extra-base hits in his debut suggest there may be enough pop for the 5-foot-11, 190-pounder to shine going forward.
Hunter Dozier, Royals
Some were caught off guard when Kansas City popped Hunter Dozier -- ranked 46th on Mayo's pre-Draft Top 100 -- with the eighth overall pick, but the Royals saved enough money with the selection to add more talent later while also perhaps finding a steal in the 22-year-old. The Stephen F. Austin product fared well with Rookie-level Idaho Falls and Class A Lexington, hitting .308 in 69 games with seven homers and an .892 OPS.
The shortstop drew 38 walks while striking out just 37 times in 273 at-bats, posting a .397 on-base percentage and smacked 30 doubles. The 22-year-old slotted seventh on the Royals' top prospect list, just behind fellow 2013 draftee Sean Manaea.
Gosuke Katoh, Yankees
New York's second-round pick Gosuke Katoh had a magnificent debut in the Rookie-level Gulf Coast League, finishing second among qualified players with a .310 average and a .924 OPS. The second baseman worked a .402 on-base percentage while collecting 22 extra-base hits and four stolen bases.
Christian Arroyo, Giants
The Giants also turned a few heads selecting Christian Arroyo with the 25th overall pick, but the shortstop rewarded San Francisco with a strong pro debut. In 45 Rookie-level Arizona League games, the Brooksville, Fla., native hit .326 with a league-best .898 OPS. The infielder's 18 doubles were best on the circuit as the 18-year-old climbed to No. 8 on the Giants' top prospect list.
Jake Seiner is a contributor to MiLB.com. Follow him on Twitter at @Jake_Seiner.