After walking to lead off the game, Julio Lugo was on first base when Los Angeles Angels pitcher Jererd Weaver attempted a pickoff.
The throw hit Lugo appeared to hit Lugo behind and just below his right ear.
He was motionless on the ground for a few moments, but he said he never lost consciousness. Eventually, Lugo sat up on the base and then walked off on his own power.
He was replaced by Jake Fox in the lineup and Ty Wigginton moved from first to second.
"It scares you when you get hit in the head," said Lugo, who had a concussion in 2007 when he hit his head against an infielder's knee. "You've got to be careful. It just happened so fast, I didn't know what was going on. … I was stunned."
Lugo, who was starting his second straight game at second for injured Brian Roberts, was examined by Angels' physicians and taken for a CAT scan during the game. He said the tests came back negative and he was not diagnosed with a concussion.
"We are going to wait and see what the doctor says tomorrow and the next day," Lugo said about when he could play again. "I felt dizzy and a little ringing in my ear, but then I was fine."