"With injuries popping up seemingly every week, the last thing the Diamondbacks wanted to see Sunday was star right fielder Justin Upton hurting his knee.

But that's what happened in the bottom of the fifth inning against the Oakland Athletics. Upton ran toward foul territory to track down a ball hit by Eric Sogard when he slipped and jammed his right knee.

Relax. It doesn't appear to be serious. Just for precaution, though, Upton left the game immediately.

"It's going to be sore," he said, "but I don't think it's anything. It shouldn't be too crazy."

Manager Kirk Gibson's stomach might have rose to his throat, but Upton said he wasn't worried when it happened."