Seattle Mariners outfielder Julio Rodriguez left Thursday's game against the Oakland Athletics in the first inning with low back tightness, the team announced.
The 21-year-old doubled in his first at-bat to lead off the game, but he departed the field with a trainer in the bottom half of the inning.
Rodriguez was replaced in the lineup by Sam Haggerty, who shifted to left field. Jarred Kelenic moved from left to center.