SAN FRANCISCO — The news of Roy Halladay's shoulder surgery has a trickle-down effect on the entire 25-man roster, and Jonathan Pettibone is one of the possible protagonists. The 22-year-old pitcher displayed competency again during a 4-3 loss Wednesday in his quest to secure a permanent rotation spot.

Pettibone was not hit hard. He threw 112 pitches in 5 2/3 innings and it was the last one that bothered him most. Barry Zito, the opposing pitcher with a lifetime batting average of .103, shot a single past a diving Kevin Frandsen at first base for an insurance run in the sixth.

"That'll haunt me for some time," Pettibone said. "I looked on the replay and it wasn't a terrible pitch, but we were pitching him like that the whole game so he was just ready for it."

The righthander holds a 3.63 ERA after four starts.

"To be his first time up in the major leagues, he's held his own," Charlie Manuel said. "He's done pretty good."

The leash was longer Wednesday than ever before in Pettibone's brief major-league career. With both Halladay and John Lannan sidelined, he is now a fixture in the rotation.

"Each time out, you get more and more comfortable," Pettibone said. "Your confidence gets up each time out. You just kind of build off that. From there, I don't really know what's gonna happen. All you can do is focus start to start and go from there."

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