Seattle Mariners acquire RHP Cooper Criswell from NY Mets

The Seattle Mariners have made an addition to their starting pitching depth, acquiring right-hander Cooper Criswell from the New York Mets for cash considerations on Friday.

To make room for Criswell on the 40-man roster, the Mariners have designated left-hander Jhonathan Díaz for assignment.

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The 29-year-old Criswell has appeared in 45 games over five MLB seasons, first debuting in 2021 with the Los Angeles Angels. Criswell has also pitched for the Tampa Bay Rays and Boston Red Sox.

Criswell’s most productive MLB season was 2024 when he pitched in 26 games for the Red Sox, including 18 starts. He finished the year with a 4.08 ERA, 1.349 WHIP and 0.7 fWAR with 73 strikeouts to 31 walks over 99 1/3 innings.

In 2025, Criswell pitched in seven games for the Red Sox with one start. He had a 3.57 ERA and 1.585 WHIP, but spent the majority of the season with Triple-A Worcester, where he had a 3.70 ERA in 16 appearances, including 14 starts.

A Georgia native and product of the University of North Carolina, Criswell was selected in the 13th round of the 2018 MLB Draft by the Angels.

The Mets had acquired Criswell last month, claiming him off waivers from Boston. The Mets designated him for assignment Wednesday after their trade with the Milwaukee Brewers for All-Star starter Freddy Peralta.

Per Statcast, Criswell features a sinker that sits around 89 mph, plus a cutter, a changeup, and a sweeper that drops down to the mid-70s.

Behind the Mariners’ usual five-man rotation, they have Logan Evans, Emerson Hancock and now Criswell on the 40-man roster as potential reinforcements. They also reportedly agreed with former Texas Rangers starter Dune Dunning on a minor league contract this week.

More Seattle Mariners offseason coverage

• M’s land four prospects on Baseball America’s new top 100
• Félix Hernández makes historic jump in HOF vote, but still has a climb to go
• Mariners agree on ’26 contract with Bryce Miller, avoiding arbitration
• Mariners have high hopes for new reliever Jose Ferrer
• Seattle Mariners add righty reliever from Cincinnati Reds

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