The Mariners added to their pitching depth on Friday, acquiring right-handed swingman Cooper Criswell from the Mets for cash.
Criswell, 29, was designated for assignment by New York on Wednesday after being selected off waivers from the Red Sox on Dec. 5. He pitched in seven games for Boston in 2025, including one start, and had a 3.57 ERA in 17 2/3 innings. Criswell made 14 starts and two relief appearances for Triple-A Worcester and had a 3.70 ERA in 65 2/3 innings.
In the Major Leagues, Criswell has spent time both as a starter and a reliever, starting 18 of his 26 games for the Red Sox in 2024 with a 4.08 ERA. He made his MLB debut for the Angels in ’21 before being claimed by the Rays in July ’22. After 11 appearances for Tampa Bay (10 out of the bullpen), Criswell signed a one-year deal with the Red Sox for ’24 before re-signing with Boston on another one-year pact.
Criswell was DFA’d by the Mets to clear a spot on the 40-man roster following New York’s trade for Freddy Peralta. He has a chance to contend for a place in the Mariners’ bullpen, whose 3.72 ERA in 2025 was the ninth best in the Majors. Criswell could also be a spot starter if Seattle’s rotation is affected by injuries.
To make room for Criswell on the roster, the Mariners designated left-hander Jhonathan Díaz for assignment.
