Zach Thornton Mets Select Prospect, Option Daniel Duarte on May 20
zach thornton mets got its roster answer on May 20, with the club officially selecting the 24-year-old right-hander and optioning Daniel Duarte in the corresponding move. Thornton is set to take on a major league role after the Mets needed another arm behind a rotation hit from Clay Holmes' fractured right fibula.
Thornton Joins The Mets
Thornton was not on the 40-man roster before the move, so the club first had to clear room before making the selection. It did that on May 19 by designating outfielder Austin Slater for assignment and recalling Nick Morabito.
The Mets drafted Thornton in the fifth round in 2023, and he entered this season among the organization’s better-regarded arms. Baseball America had him at No. 13 in the system entering 2026, while FanGraphs listed him at No. 12 before its update pushed him to No. 10 on May 20.
Mendoza's Wednesday Plan
Manager Carlos Mendoza set the frame two days earlier, saying on May 18 that Thornton would play some kind of role for the Mets on Wednesday. That role can take a couple of forms: he could start, or he could work as a bulk guy behind an opener.
Thornton has already done enough this season to make the call-up make sense. Before the promotion, he 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.
Clay Holmes Opens The Door
The opening came because Holmes fractured his right fibula and might be sidelined into August. Wednesday would have been his turn in the rotation, so Thornton will at least get a spot start while the Mets sort out the next turn.
Thornton’s broader profile is built on strike throwing and contact management. In 2025, he made 14 starts, logged 72 2/3 innings between High-A and Double-A, posted a 1.98 earned runs per nine mark, struck out 28.5% of batters faced, walked 4% of opponents and induced grounders on 43.2% of balls in play.
His fastball averaged 91 miles per hour, and his mix includes a four-seamer, sinker, slider, cutter, curveball and changeup. That gives the Mets a multi-pitch option they can use in different ways, even if the spot start does not lock him into a long major league stay.
The club can send Thornton back to the minors after the spot start. If it chooses another route for Holmes’ next turn, Sean Manaea or Tobias Myers are listed as options, with Jonah Tong, Jack Wenninger and Jonathan Pintaro also in the farm mix.
