Hart (shoulder) offered some more context regarding his injury, revealing that he suffered the shoulder impingement while fieldng a fly ball during batting practice, the Pittsburgh Post-Gazette reports. "During BP, somebody hit a ball and I kind of just reached back to grab it and it kind of jerked it back," Hart said. "Ever since then it's been kind of ongoing." Hart said he believes he aggravated the injury while trying to hit in subsequent days, and stated that his stay on the DL is precautionary, more than anything else. "I think I overdid it trying to hit during the games and just kind of aggravated it enough to where it needed to take three, four, five days off and try to start back," Hart said. "It's more cautious than anything. It hurts, so I'm just trying to nip it in the bud so it doesn't cost me longer than a couple weeks."