Whatever it was, he hit it hard, and he banged up his knee.
"It was a direct shot," said Kelly, who eventually left Thursday's 2-1, 10-inning win over the Cardinals with a left knee contusion. "It hit on the outside on like a post, I think, and then I have two gashes in it from where I hit the wire part [of the fencing]."
Kelly caught the fifth-inning fly ball in foul territory in right field. It allowed Rafael Furcal to score, tying the game with what ended up being the Cardinals' lone run of the afternoon, but it also retired Matt Holliday and allowed the Tigers to intentionally walk Carlos Beltran and set up Allen Craig for the final out of the inning to limit the damage.
Kelly played the next couple innings before giving way to Ryan Raburn in right in the eighth inning. He's listed as day to day.
"I was trying to go. It just kept getting tighter and tighter," Kelly said. "And then I tried to make a throw to second base on [Daniel] Descalso [who doubled in the seventh], and I just couldn't get over my front side to throw. It was better for somebody else to be out there."
Kelly is hopeful that ice and treatment will allow him to be available for this weekend's series in Pittsburgh, his hometown. He'll be part of the pregame ceremonies Sunday, when the Pirates honor his alma mater, Point Park University, for its berth in the NAIA World Series this spring.