Hart (shoulder) was placed on the 15-day DL on Wednesday, Stephen J. Nesbitt of the Pittsburgh Post-Gazette reports. Hart is battling a shoulder impingement, which could partially explain why he's seen time in only seven games this month. The veteran is without a firm timetable, but given the timing of his DL placement, he figures to return shortly after the All-Star break. In a corresponding move, the Pirates recalled right-hander Chris Volstad from Triple-A.