In a move that could reshape their bullpen, the Seattle Mariners have quietly made a strategic acquisition—but is it enough to boost their playoff chances? The Mariners announced on Friday that they’ve acquired right-handed pitcher Cooper Criswell from the New York Mets in exchange for cash considerations. This under-the-radar deal comes as part of a broader roster shuffle, with left-hander Jhonathan Diaz being designated for assignment to make room. But here’s where it gets interesting: Criswell, 29, isn’t exactly a household name, but his recent performance hints at untapped potential. Last season, he appeared in seven games for the Boston Red Sox, posting a respectable 1-0 record with a 3.57 ERA—numbers that suggest he could be a reliable arm in the Mariners’ bullpen. However, his journey to Seattle hasn’t been without twists. After being claimed off waivers by the Mets on December 5, he was designated for assignment just this past Wednesday, raising questions about his long-term role. Meanwhile, Diaz’s departure is equally noteworthy. Despite a standout 2025 season in Triple-A Tacoma, where he went 11-6 with a league-leading 4.15 ERA, his lone appearance with the Mariners last year didn’t translate into a permanent spot. And this is the part most people miss: While Criswell’s addition seems like a low-risk, high-reward move, it also underscores the Mariners’ ongoing struggle to solidify their pitching staff. Is this a smart gamble, or just another bandaid on a deeper issue? Let us know your thoughts in the comments—do you think Criswell can make a meaningful impact, or is this just another footnote in Seattle’s quest for postseason success?
