The Mariners placed Criswell on the 15-day injured list Tuesday with a right shoulder strain.
Criswell has given up three earned runs in 1.1 combined innings over his last two appearances, and he appears to have come away from his latest outing Monday with shoulder trouble. He'll take at least two weeks off to recover, and Nick Davila will come up from Triple-A Tacoma to replenish Seattle's bullpen depth.