Mercer was spiked in his right ankle at second base in the third inning by the Brewers' Martin Maldonado, who had walked and was forced out at second base when Kyle Lohse tried to move him over with a bunt. Lohse was called safe at first.
Mercer remained in the game and singled in the bottom of the frame, but was limping badly on his way to first and didn't take the field for the fourth.
"He clipped me with his spikes," Mercer said after the game. "I wasn't cut. It's just a bad bruise. It is very sore. We'll see how it feels tomorrow."
George Von Benko is a contributor to MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.