The Pirates placed reliever Rob Scahill on the 15-day disabled list with right forearm tightness and recalled RHP Deolis Guerra from Class AAA Indianapolis.
Scahill has appeared in 24 games and has a 2-4 record with a 2.08 era but he gave up the game-winning home run in the Pirates 5-4 loss to the Reds Thursday.
Guerra, 26, was signed as a minor league free agent last November and this is first trip to the majors.
He was 2-1 with four saves and a 1.23 ERA in 25 games with Indianapolis and he has not allowed a run in his last 11 appearances.