OAKLAND (AP) — Athletics pitcher Brandon McCarthy left in the fourth inning of Wednesday's 7-1 loss to the Los Angeles Angels after Erick Aybar's hard line drive ricocheted off the right-hander's head.

McCarthy was taken to Alta Bates Summit Medical Center in Oakland as a precaution, and the team said doctors wanted him to stay overnight for further observation. The A's also announced McCarthy would not travel with the team to Seattle on Thursday.

McCarthy had almost no time to react when Aybar lined his 91-mph cutter back up the middle. The ball bounced off the right side of McCarthy's head, knocking him down. He also landed on his head on the infield grass.

Third baseman Josh Donaldson picked up the deflected ball and threw to first for the second out of the inning.

McCarthy curled up in a ball and was writhing in pain. Team trainers checked on McCarthy for several minutes as A's players huddled around the infield and on the top step of the dugout.

Aybar stood on first base and looked on with concern. He was later seen in the Angels' dugout sitting with his head down and his hands over his head.

McCarthy eventually sat up and ran his hands through his hair and around his head. He walked off the mound under his own power to an ovation from the Oakland Coliseum crowd.

McCarthy left with Oakland trailing 3-1. He allowed five hits, struck out three and walked one intentionally. Travis Blackley entered in relief.

McCarthy, Oakland's opening-day starter, is 8-6 with a 3.24 ERA in 18 starts this season.