Castillo appears to be making good progress in his recovery from a hamstring strain, and the Mariners remain cautiously optimistic that he'll be activated from the 15-day injured list when first eligible Monday, MLB.com reports. "Progressing as he should be," manager Dan Wilson said. "I don't think there's any expected date, right now, of his return, but progressing as he has. I know Luis is very diligent about getting his work in and trying to get healthy, and I think as far as we know right now, he's doing well."
The veteran right-hander has been sidelined since Sept. 8, when he suffered the strain while ducking out of the way of a throw on a stolen-base attempt. Castillo's ability to make at least one more start down the stretch could be critical for the Mariners, who remain in contention for an American League wild-card spot entering the season's final week. Castillo has once again proven a consistent workhorse of Seattle's rotation this season, going 11-12 with a 3.64 ERA and 1.17 WHIP across 175.1 innings over 30 starts.