Schafer reached on an error to start the inning and was thrown out trying to steal second base on a head-first slide, but his head struck the knee of Marlins shortstop Jose Reyes, who applied the tag. Schafer walked off the field under his own power and was taken out.
"His knee kind of hit me in the head, and I got real dizzy," Schafer said. "I feel fine. It's nothing serious."
Schafer went 0-for-5 with a walk Sunday against the Marlins and has reached base safely in all nine games this season. He's hitting .242 with a .405 on-base percentage and has walked nine times as the leadoff hitter.