Mariners starting pitcher James Paxton has left Seattle's home opener against the Los Angeles Angels after straining a muscle in his left side.

Paxton left in the top of the sixth inning. The team announced a preliminary diagnosis of a strain of the left lat muscle. Paxton will have an MRI on Wednesday but after the game did not seem concerned about it being a long-term injury.

"You want to be careful this time of year. You don't want to push it too hard," Paxton said.

Paxton, a 25-year-old left-hander from Richmond, B.C., had retired 14 straight batters entering the sixth. Kole Calhoun snapped the streak with a single leading off the inning.

Paxton threw one pitch to Mike Trout, and manager Lloyd McClendon and athletic trainer Rob Nodine immediately went to the mound. Paxton appeared to point toward the back of his left shoulder and arm, and was removed from the game. He was replaced by Yoervis Medina.

Paxton actually felt a twinge in the muscle in the fifth inning, but finished the inning and felt fine taking the mound for the sixth.

Paxton gave up three runs and four hits in five-plus innings.