Since Sept. 26, Peavy has started just one game, which is why he volunteered for bullpen duty in advance of his next start, which will be Game 4 of the ALCS on Wednesday.
"Out of fairness to Jake, and in fairness to all, we've got guys who are familiar with certain roles," said manager John Farrell. "And while there wouldn't be [any hesitation] to use a starter, it would have to be a specific situation. In other words, I'm not jumping him ahead of [Junichi] Tazawa or maybe even [Brandon] Workman in a certain situation."
Felix Doubront and Ryan Dempster, both of whom pitched in the rotation almost all season, will again be in the bullpen throughout this series.
Doubront didn't pitch in the Division Series.
"Again, it's going to be factored upon if we've already used guys in a certain point of the game, and we feel like a left-hander is best suited for a certain spot in the lineup," said Farrell. "He's on the roster, so there isn't going to be hesitancy to use him."
Ian Browne is a reporter for MLB.com. Read his blog, Brownie Points, and follow him on Twitter @IanMBrowne. Jason Mastrodonato is an associate reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.