McCutchen was added to the roster on Saturday after the Pirates placed Ross Ohlendorf on the disabled list.
The Pirates were in desperate need of a fresh arm -- specifically a pitcher who could pitch multiple innings -- after the bullpen was drained in Friday's 4-3 win over Colorado. The 'pen logged 11 1/3 innings, and all six healthy relievers made an appearance.
The heavy workload meant that Chris Resop, Garrett Olson, Jeff Karstens and Mike Crotta were deemed unavailable for Saturday's game. Evan Meek was as well, though that decision was because of tightness in the right-hander's shoulder.
While the bullpen recovers, McCutchen will be manager Clint Hurdle's first option if the club needs someone to pitch in long relief. Expecting to begin the season as a starter, McCutchen threw 75 pitches in an extended Spring Training game on Tuesday. He had tossed 68 in the outing before that.
Pittsburgh might have considered Brian Burres or Chris Leroux for the callup instead, but both pitched recently. Burres, who isn't on the 40-man roster, started for Indianapolis on Thursday. Leroux only tossed an inning on Friday, but he is not as stretched out as McCutchen
"He's done some good things," Hurdle said of McCutchen, who made 19 appearances out of the Pirates' bullpen last year. "He's got good stuff, and he's very competitive. He's a good guy for us to be able to have."