Jonathan Pettibone will start Saturday's game, the first in which the Phillies require a fifth starter, but could make just two turns through the rotation. Pettibone, who battled shoulder soreness in spring training, earned the nod over David Buchanan and Jeff Manship.
"Pettibone earned an opportunity to pitch with us," Ruben Amaro Jr. said. "He got hurt. He was still fairly effective and he was still learning but we think he's got a strong future as a starter for us. As long as we felt he was aggressive and healthy, he was probably the No, 1 candidate going in anyway."
Cole Hamels will start Saturday for single-A Clearwater. He will pitch again for the Threshers on April 17. That positions him to pitch April 22 at Dodger Stadium.
The Phillies must subtract a reliever before Saturday's game to add Pettibone.