Houston Astros pitcher Cody Bolton exited Sunday's game against the Seattle Mariners in the second inning due to mid-back tightness. The 26-year-old rookie, making his second major league start, walked his first three batters before being joined on the mound by manager Joe Espada and an athletic trainer.

The injury comes just days after Bolton was hit by a 102.5 mph line drive on his back during his debut last Monday, when he still managed to throw 4⅓ innings in a 9-7 loss. Espada said the tightness occurred in the same area where Bolton was struck by the line drive. The Astros have now lost three starting pitchers during their 10-game trip, going 1-8 heading into Monday's series finale.

Houston's pitching staff has been decimated by injuries, with Tatsuya Imai returning to Houston for examination of right arm fatigue and Cristian Javier placed on the injured list Friday with a right shoulder strain. Hunter Brown, who Bolton replaced in the rotation, was placed on the 15-day IL on April 5 with a right shoulder strain. The last-place Astros were also without All-Star shortstop Jeremy Peña, who left Saturday's game with a right knee injury.