But Pettibone fared well in his rookie season. He went 5-4 with a 4.04 ERA in 18 starts.
"He showed some good things," Phillies interim manager Ryne Sandberg said. "He showed some growth. He showed composure out there. He pitched some quality games. He gave the team a chance to win. I had him in Lehigh Valley and it was the same stuff. I think it was a good experience for him. I think he showed he can do it. He just had a real good look about him out there."
Pettibone is getting a second opinion on his shoulder from Dodgers physical Neal ElAttrache.
"We're going to be cautious with him," general manager Ruben Amaro Jr. said. "We don't want to mess with Jonathan too much."
Todd Zolecki is a reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.