The Pirates placed Priester on the 15-day injured list Thursday with a right lat injury, Alex Stumpf of MLB.com reports.
Priester allowed four earned runs in 4.2 innings during his latest start Sunday, and he appears to have come away from the game with lat problems. His move to the IL is retroactive to Monday, so the 24-year-old righty will be eligible for activation beginning June 18. In the meantime, Justin Bruihl, who signed a big-league contract with the Pirates on Thursday, will fill the open spot on Pittsburgh's pitching staff.