.285/.395/.579, 132 G, 36 HR, 1 3B, 31 2B, 119 RBI
MLB Organization: Mets
Alonso was known for his power but managed 18 homers over 93 games in 2017 while limited with a broken hand. This season, he was arguably the Minors' most prolific power hitter, finishing tied at the top in homers while slugging .579 across the upper two levels of the Mets' system. That pop has pushed him into the top-100 ranks for the first time in his career, and he's in the conversation for No. 1 first-base prospect.
6-1, 2.89 ERA, 56 IP, 67 K, 8 BB, 1.16 WHIP
MLB Organization: Yankees
The Yankees showed trust in Loaisiga by adding him to the 40-man roster last fall, despite having pitched only 2 1/3 innings at Class A or above. He rewarded that trust by posting a 2.89 ERA with 67 strikeouts and eight walks over 56 innings across three Minor League levels, and by mid-June, he received his first Major League look. Armed with three above-average pitches and good control when healthy, Loaisiga is MLB.com's No. 66 overall prospect.
7-3, 2.10 ERA, 90 IP, 120 K, 8 BB, 0.82 WHIP
MLB Organization: Padres
The 22-year-old threw only 42 1/3 innings in 2016 before a forearm strain and Tommy John surgery knocked him out for the rest of the season and all of 2017. He returned to the mound in 2018 as San Diego's No. 23 prospect but moved up to No. 35 overall by season's end, showing impressive control along with a plus fastball and plus-plus changeup. His remarkable 15-to-1 strikeouts-to-walk rate was tops among Minor League pitchers with at least 80 innings.
.348/.392/.578, 130 G, 20 HR, 7 3B, 44 2B, 101 RBI, 4 SB
MLB Organization: Twins
The 2016 15th overall pick didn't play at all in 2017 after undergoing Tommy John surgery but showed no rust upon his return. The 20-year-old led the Minors with 71 extra-base hits and batted .348 with a .970 OPS between Class A Cedar Rapids and Class A Advanced Fort Myers, despite the long layoff. He's now MLB.com's No. 10 overall prospect after opening 2018 outside the top 100.
8-5, 3.44 ERA, 125 2/3 IP, 143 K, 36 BB, 1.19 WHIP
MLB Organization: Braves
The Braves right-hander opened the season at Class A Advanced Florida. He finished it in the Majors with the NL East division winner. Wilson posted a 3.44 ERA with 143 strikeouts and 36 walks over 125 2/3 innings across three Minor League levels and even set at Triple-A Gwinnett record with 13 K's on Aug. 15. In a system loaded with arms, he's carved out what could be a big role in Atlanta going forward.
.290/.355/.543, 99 G, 20 HR, 4 3B, 32 2B, 77 RBI, 15 SB
MLB Organization: Angels
The 2017 10th overall pick became one of the Minors' most electric players quickly in his first full season, and the Angels treated him accordingly, bumping him up three levels in his age-19 season. Adell produced an .897 OPS with 20 homers and 15 steals between Class A Burlington, Class A Advanced Inland Empire and Double-A Mobile, becoming a consensus top-20 overall prospect as a result.
.252/.388/.499, 132 G, 26 HR, 5 3B, 23 2B, 99 RBI, 20 SB
MLB Organization: Blue Jays
Biggio entered the season as the least well-known son of a Major Leaguer in the New Hampshire infield. He finished it as Eastern League Rookie of the Year and MVP, hitting 26 home runs while collecting 20 steals in the Double-A circuit. Unranked at the start of the season, the 2016 fifth-round pick out of Notre Dame now sits in the No. 9 spot in the Blue Jays' system.
6-4, 3.23 ERA, 114 1/3 IP, 171 K, 49 BB, 1.12 WHIP
MLB Organization: Astros
The 25-year-old wasn't ranked among the top 30 prospects in the Astros system to begin 2018 but ended up being one of the Minors' toughest pitchers to touch this season. James' 171 strikeouts between Double-A Corpus Christi and Triple-A Fresno tied for fourth-most in the Minors, helping him earn his first Major League call-up when rosters expanded in September. James is now ranked as the Astros' No. 4 prospect and No. 95 overall by MLB.com.
.351/.418/.587, 61 G, 11 HR, 7 3B, 10 2B, 57 RBI, 4 SB
MLB Organization: Rays
The Rays liked the Dominican Republic native enough to send him stateside one year after signing him, and the 17-year-old beat even their expectations. Franco was the Appalachian League Player of the Year after hitting .351/.418/.587 with 11 homers and a 19/27 K/BB ratio in 61 games for Princeton. Now ranked No. 14 overall, the switch-hitting shortstop is primed to be the game's next young phenom.
4-3, 3.65 ERA, 113 1/3 IP, 125 K, 44 BB, 1.26 WHIP
MLB Organization: Angels
Taken by the Angels in the second round in 2017, the UCLA product has proven to be one of the fastest movers of that Draft class. Canning posted a 3.65 ERA with 125 strikeouts in 113 1/3 innings across three levels, finishing with 13 starts for Triple-A Salt Lake. Selected with the No. 47 overall pick, he's now MLB.com's No. 72 overall prospect.