The son of collegiate track athletes Paul and Julie- the latter of whom was inducted into the St. Olaf College Hall of Fame- Zach Thornton attended Lawrence Free State High School in Lawrence, Kansas. Far from a must-follow prospect and last having pitched in his junior season thanks to the cancellation of the 2020 season due to the COVID-19 pandemic, the left-hander went undrafted in the 2020 MLB Draft. Along with three other Firebirds teammates, Thornton attended Barton Community College, a junior college
in Great Bend, Kansas, a few hours away from Lawrence.
Overview
Name: Zach Thornton
Position: LHP
Born: 01/17/2002 (Age 24 season in 2026)
Height: 6’3”
Weight: 170 lbs.
Bats/Throws: L/L
Acquired: 2023 MLB Draft, 5th Round (Grand Canyon University)
2025 Stats: 4 G (4 GS), 20.2 IP, 12 H, 5 R, 1 ER (0.44 ERA), 2 BB, 25 K, .229 BABIP (High-A) / 10 G (10 GS), 52.0 IP, 36 H, 16 R, 15 ER (2.60 ERA), 9 BB, 53 K, .252 BABIP (Double-A)
There, he joined the Barton baseball team and appeared in 14 games for the Cougars, starting 13 of them. In 60.2 innings, he posted a 4.01 ERA, allowing 58 hits, walking 21, and striking out 79. Following the conclusion of the season, he pitched for the Great Bend Bat Cats of the Sunflower Collegiate League, where he posted a 4.18 ERA in 32.1 innings, allowing 33 hits, walking 18, and striking out 41. He returned to Barton for his sophomore season and appeared in 15 games, starting all 15, posting a 2.63 ERA in 78.2 innings, with 60 hits allowed, 26 walks, and 91 strikeouts.
That summer, he returned to Great Bend and played with the Elizabethton River Riders of the Appalachian League and the Mahoning Valley Scrappers of the MLB Draft League as well. This supplemental pitching work, combined with his performance at Barton Community College, led to the southpaw being offered a spot at Grand Canyon University. A mainstay in their weekend rotation, Thornton posted a 3.87 ERA in 88.1 innings with the Antelopes, allowing 99 hits, walking 18, and striking out 91 in his first taste of NCAA Division I baseball. After the season ended, the 21-year-old once again pitched some supplementary innings, this time with the West Virginia Black Bears of the MLB Draft League.
The Mets selected the southpaw with their 5th round pick in the 2023 MLB Draft, signing him for $350,000, $28,000 below the MLB-assigned slot value for the 159th overall selection, $378,000. The Mets elected to not have Thornton play for the rest of the season, and his professional career began instead in 2024. Assigned to Single-A St. Lucie to begin the year, the left-hander appeared in 13 games, making 6 starts and posting a 4.39 ERA in 41.0 innings, allowing 47 hits, walking 16, and striking out 32. He was promoted to the High-A Brooklyn Cyclones in August and finished out his season in Coney Island, posting a 3.67 ERA in 27.0 innings, allowing 30 hits, walking 2, and striking out 22. All in all, Thornton posted a combined 4.10 ERA in 68.0 innings in his first professional season, allowing 77 hits, walking 18, and striking out 54.
Remaining in Coney Island to begin 2025, Thornton started the season off on fire, making 4 starts with Brooklyn and allowing a single earned run in 20.2 innings while scattering 5 hits, walking 2, and striking out 25. The Mets promoted him to Double-A Binghamton at the end of April but he did not miss a beat, continuing to dominate the more advanced hitters of the Eastern League. Thornton had his season end prematurely in early July due to an oblique injury, but in the 52.0 innings that he did pitch, the lefty was electric. Making 10 starts, he posted a 2.60 ERA with 36 hits allowed, 9 walks, and 53 strikeouts. In total, Thornton posted a cumulative 1.98 ERA in 72.2 innings over 12 starts, allowing 48 hits, walking 11, and striking out, his 7.09 K:BB ratio the best in the system among pitchers who threw 25.0 or more innings.
The 6’3”, 170-pound left-hander throws from a high-three-quarter arm slot and has plenty of deception in his delivery with a funky, up-tempo delivery that incorporates an extremely long arm action through the back and a slingy, crossfire release. Despite all of the movement in his delivery, Thornton has above-average command of all of his pitches. He can pound the zone with pitches, throw borderline pitches to get batters to chase, and work to all quadrants of the zone with all of his pitches. While no one pitch that the left-hander throws is more than an average offering, his large repertoire keeps batters guessing and his impeccable command helps all of those pitches play up to their greatest potential. Coming into the 2025 season, he made attacking batters and putting them in pitcher’s counts earlier a goal, a strategy that paid major dividends for him.
Thornton throws a four-seam fastball and a two-seam fastball, and while the two pitches bleed into each other a great deal, they remain two distinct pitches and two distinct grips that the left-hander uses. Coming into the 2025 season, his fastball generally sat in the high-80s-to-low-90s, topping out as high as 95 MPH, but after doing off-season weight and strength training, his fastball has more consistently sat in the low-to-mid-90s. When thrown up in the zone, his four-seam fastball has averaged a slightly above-average induced vertical break a bit over 15 inches, while his two-seam fastball has roughly MLB average downward and horizontal movement.
The left-hander’s slider generally has been his most effective strikeout pitch. Like his fastball, off-season weight training during the winter of 2024-2025 gave his slider a little extra velocity, and the pitch now sits comfortably in the mid-to-high-80s, previously sitting more in the low-to-mid-80s. The pitch has slurvy two-plane break, and like his other breaking balls, works best down in the zone thanks to its vertical drop.
Rounding out his arsenal is a curveball and changeup. His curveball sits in the mid-70s and has big 11-5 break, while his changeup sits in the low-80s with late fade and tumble. Both pitches generally induce more weak ground balls or lazy fly balls than strikeouts; In 2024, the left-hander had a 49.5% groundball rate and 25.0% flyball rate, and while both have regressed, the 43.2% and 35.2% rates he posted, respectively, still make Thornton an effective pitcher.
2026 Mets Top 25 Prospect List
15) Nick Morabito
16) R.J. Gordon
17) Chris Suero
18) Dylan Ross
19) Ryan Lambert
20) Antonio Jimenez
21) Edward Lantigua
22) Eli Serrano III
23) Randy Guzman
24) Daiverson Gutierrez
25) Boston Baro
