The Seattle Mariners have placed starting pitcher Luis Castillo on the 15-day injured list due to a Grade 2 left hamstring strain sustained during his recent start against the St. Louis Cardinals. Mariners GM Justin Hollander indicated that while Castillo received a PRP injection, there is optimism he could return within the minimum stint, as he has a history of being a fast healer. Castillo, who has been a crucial part of the Mariners’ pitching rotation, holds a 3.64 ERA and has made 30 starts this season. This injury marks only the second time this season a Seattle starter has been placed on the IL, the first being Bryan Woo. With just 18 games remaining and a tight race for a wild card spot, the Mariners are exploring options to fill Castillo's spot in the rotation, potentially recalling Emerson Hancock. Castillo expressed uncertainty about the injury's cause, noting it may have stemmed from an abrupt movement while fielding a play during the game.