The Mariners got a small but useful roster lift on August 31, 2026, reinstating Cooper Criswell from the 60-day injured list. It is not the kind of move that changes the shape of a season by itself, but it does matter for a club that has spent much of the year managing its pitching staff in layers.
Criswell had been out since June with a pectoral strain, first landing on the 15-day injured list before being transferred to the 60-day injured list later in 2026. His return gives Seattle another relief option at a time when the Mariners have already had to shuffle pitchers to the bullpen and lean on six-man rotations when the schedule or staff depth required it.
Why the move matters
What makes Criswell relevant is the role he filled before the injury. Early in the season, Seattle used him in relief because the club had plenty of starting options. That flexibility is part of the reason the Mariners were willing to acquire him in the offseason, after he was out of options and had been claimed by the Mets before Seattle sent cash to Queens to bring him in.
The numbers help explain why he remains part of the conversation. Across 26 appearances, Criswell posted 30 2/3 innings with a 3.52 earned run average, a 19% strikeout rate and a 6% walk rate. That is not overpowering stuff, but it does point to a pitcher who can keep traffic manageable and offer usable innings without forcing the bullpen into constant recovery mode.
There is also a practical layer here: the Mariners did not need Criswell to be the headline act, they needed him to be available. In a stretch run, that matters more than it might in April. A back-end relief arm who can absorb innings, stabilize a game and avoid free passes can be valuable simply because he reduces the need for another move the next day.
For Criswell, the timing is important too. He was acquired in the offseason, lost time to injury in June and now returns with the Mariners still trying to preserve pitching depth across the staff. That sequence does not create a major headline, but it does tell a familiar October-adjacent story: the teams that survive tend to be the ones that can keep adding competent arms when the calendar starts to tighten.
