Angels catcher Bobby Wilson was hurt on Friday night against the Yankees in his first major league start.
Wilson was bowled over by Yankees first baseman Mark Teixeira during a collision at home plate in the third inning. Wilson's head slammed into the dirt, which led to a concussion.
He also hurt his ankle in the incident.
Wilson was removed from the game and taken to a local hospital in Los Angeles for tests.
The Angels already were without starting catcher Jeff Mathis, who is out for at least six weeks after taking a pitch off his right wrist.
Wilson Hurt In First Major League Start