The Seattle Mariners continued to reshape their roster this week, adding another arm to an already strong pitching staff. According to ESPN’s Jorge Castillo, Seattle acquired right-handed pitcher Cooper Criswell from the New York Mets in exchange for cash considerations after the Georgia native was designated for assignment.
Mariners Add Pitching Depth With Cooper Criswell Trade
The Mets moved Criswell off their roster. The decision came following a series of moves that included acquiring Freddy Peralta and Tobias Myers from the Milwaukee Brewers. A deal that forced New York to make space on its 40-man roster.
Criswell, 29, made his MLB debut in 2021 with the Los Angeles Angels. He has since spent time with the Tampa Bay Rays, Boston Red Sox, and the Mets. While he bounced between organizations, he contributed as both a starter and reliever, a combination that likely interested Seattle.
His most productive season came in 2024, when he appeared in 26 games, including 18 starts, primarily with Boston. Over 99 1/3 innings, Criswell posted a 4.08 ERA, 1.35 WHIP, and 0.7 fWAR. He struck out 73 batters while issuing 31 walks. Though not dominant, he provided steady innings and filled multiple roles throughout the season.
Criswell’s 2025 campaign was more limited. He appeared in just seven major-league games with one start for the Red Sox before spending most of the year with Triple-A Worcester. At the minor-league level, he recorded a 3.70 ERA across 16 appearances, including 14 starts. This suggests that he is capable of handling a heavy workload despite fewer big-league opportunities.
From a pitch-mix standpoint, Criswell relies more on movement and deception than raw velocity. According to Statcast, his sinker averages around 89 mph, complemented by a cutter, changeup, and a sweeper that drops into the mid-70s. His profile fits Seattle’s recent trend of targeting pitchers who can garner weak contact and generate ground balls.
To make room for Criswell on the 40-man roster, the Mariners designated left-handed pitcher Jhonathan Díaz for assignment.
Criswell’s Spot in the Rotation
With one of the stronger starting rotations in baseball, the Mariners continue to prioritize their pitching depth. The projected starters of Logan Gilbert, George Kirby, Bryan Woo, Bryce Miller, and Luis Castillo rank among the league’s best, but injuries and workload mean reliable depth is essential throughout the entire season.
Beyond that group, pitchers such as Logan Evans, Emerson Hancock, and Blas Castaño remain largely uncertain at the major-league level. Highly regarded switch-pitching prospect Jurrangelo Cijntje is advancing through the system. However, with just seven Double-A starts and no Triple-A experience, he is likely not ready for the big leagues yet.
Criswell could compete for a role, despite an already crowded bullpen. Seattle currently expects an eight-man relief group consisting of Andrés Muñoz, Matt Brash, José A. Ferrer, Eduard Bazardo, Gabe Speier, Carlos Vargas, Casey Legumina, and Jackson Kowar.
Only Brash and Ferrer have minor-league options remaining, but both are viewed as key bullpen players. As a result, the Mariners may attempt to pass Criswell, or another arm, through waivers at some point to gain additional roster flexibility as the offseason continues.
Mariners Add Pitching Depth in Trade With Mets