Peavy is penciled in to start against the Padres on Sunday, Andrew Baggarly of the Mercury News reports. A back issue will keep Peavy from making his debut Tuesday against Arizona, but he said he was hoping to make his next start and the Giants seem to think he will. Peavy revealed that his back first locked up last week, but he has been responding positively to treatment. Ryan Vogelsong is starting in Peavy's place Tuesday.