Walker was removed in the ninth inning of Saturday's game against the Red Sox after being hit in the head by a pitch, Mac Cerullo of the Boston Herald rpeorts.
Walker was hit in the head by a 93-mph fastball from Tyler Samaniego, which resulted in the former's helmet cracking. Walker was immediately taken out of the game, and an update on his status should come after the contest. Braden Shewmake entered the game as a pinch runner following Walker's exit.