The Mariners selected Castillo's contract from Triple-A Tacoma, and he's scheduled to start Friday against the Giants.

EDGE Analysis

The right-hander allowed one run over 5.2 innings during his lone start for Tacoma this year and will now get a look in the big-league rotation. Castillo's only major-league experience came with Detroit in 2022, when he delivered a 4:0 K:BB over 3.2 scoreless frames in three appearances. He spent the 2023 and 2024 campaigns pitching in Japan and had a 3.01 ERA across 143.1 innings before inking a minor-league deal with Seattle during the offseason.