As Matt Kemp ran to first base while grounding out in the third inning Sunday against Colorado, Dodgers Manager Don Mattingly could tell something wasn't right with his center fielder.

Kemp had strained his left hamstring a week earlier, and now it appeared he had aggravated the injury again.

So as Kemp started to take the field in the fourth inning, Mattingly said he told the slugger, " 'Matt, if you feel anything at all, you can't go out there.'"

"That's when he turned around" and back toward the bench, Mattingly said, confirming the manager's suspicion. Kemp then threw his cap and glove into the dugout.

"I wasn't mad at Donnie," Kemp said. "I'm just frustrated — kind of haven't been able to play as I want to play."