Mariners right-hander left Sundays game due to a strain in his left hamstring, and will undergo an MRI on Monday to a se s the damage. Castillo told reporters (including ) via interpreter that some discomfort first arose in the fourth inning when he moved on the mound to evade a throw that never came from catcher on an stolen base. Two pitches after Herreras steal, Castillo grimaced on the mound after his follow-through, and left the game after a visit from trainers. The discomforts there. Tomorrow were going to get some [tests] done, just to see what it is, but hopefully its not too bad , Castillo said. With the Mariners battling for either the AL West title or a wild card, losing Castillo would put a serious dent in the clubs playoff Karl-Anthony Towns Jersey hopes. Seattle ranks at or near the bottom of the league in several major offensive categories, yet the Ms have been carried by their elite rotation. The rotation has been both effective and durable of the 21 starters who have to sed at least 161 1/3 MLB innings this season, four of them (Castillo, , , and ) pitch for Seattle. has had a pair of IL stints, with stepping into the rotation in Woos place to take nine starts. Hancock (currently at Triple-A) is the likeliest candidate to return to the staff if Castillo has to go on the injured list, yet the former top prospect hasnt been very consistent against big league hitters. Hancock has a 4.76 ERA in 45 1/3 innings and a 4.50 ERA in 12 innings in his 2023 debut season, and only a 13.8% strikeout rate in his brief MLB career. While Hancock is a better sixth starter than most clubs po se s, theres still no easy way to replace Castillo. The three-time All-Star hasnt been quite as effective as he was when finishing fifth in AL Cy Young Award voting in 2023, but Castillo still has a 3.64 ERA over 175 1/3 innings this year. His strikeout and walk rates are still above the league average, and while Castillos four-seamer has dropped in velocity from 96.3mph in 2023 to 95.5mph this season, it remains one of the most effective pitches in baseball. James Johnson Jersey