The Mets are promoting pitching prospect Zach Thornton this week, and manager Carlos Mendoza said the 24-year-old will have some kind of role on Wednesday. The club will at least give Thornton a spot start as it tries to cover for the injured Clay Holmes.
Thornton could work either as a starter or as a bulk arm behind an opener, giving the Mets a flexible option for a rotation turn that had belonged to Holmes. The right-hander is not yet on the 40-man roster, so the team must clear room before the move becomes official.
The call-up gives the Mets a look at a pitcher whose stock has risen fast over the past two seasons. Thornton, a fifth-round pick in 2023, made 14 starts in 2025 before an oblique injury ended his season. Between High-A and Double-A that year, he threw 72 2/3 innings and allowed 1.98 earned runs per nine, while striking out 28.5% of batters faced, walking 4% and inducing grounders on 43.2% of balls in play.
He entered 2026 ranked No. 13 in the system by Baseball America and No. 12 by FanGraphs, and Baseball America later moved him up to No. 10. In 2026, Thornton made five Double-A starts and two Triple-A starts, covering 37 innings with a 3.16 ERA, a 26.5% strikeout rate, a 7.9% walk rate and a 44.4% ground ball rate. He averages 91 miles per hour with his fastball and works with a full mix that includes a four-seamer, sinker, slider, cutter, curveball and changeup.
Holmes fractured his right fibula and might be sidelined into August, forcing the Mets to improvise while they sort out the next stretch of the rotation. Christian Scott is starting tonight, Nolan McLean is starting tomorrow, and the club is also weighing Sean Manaea and Tobias Myers for the next turn. Thornton’s promotion is part answer, part test: he gives the Mets a live arm now, but after Wednesday they could still send him back to the minors if the roster math and the rotation picture demand it.
