But heading into Game No. 162, he's the most reliable relief pitcher the Red Sox have aside from their closer, Jonathan Papelbon.
Aceves again bailed out the Red Sox on Tuesday night, going longer than starter Erik Bedard did in an 8-7 win over the Orioles that kept Boston tied with the Rays in the American League Wild Card chase. Aceves went 3 2/3 innings -- on the third consecutive day he's pitched -- and allowed one run on three hits, while Bedard went 3 1/3 innings and gave up three runs.
"I just want to contribute to my team. I want to help my teammates to win," Aceves said when asked if he thought his role would be this crucial. "As a leader to my friends and teammates. ... This last month, it's like the playoffs. There's no margin of error in here."
On Tuesday, just nine of Aceves' 36 pitches missed the strike zone. It was the 13th time this season he had gone three innings or longer -- and the fourth in September. His longest outing of the season as a reliever was 4 2/3 innings, in April.
Entering Wednesday, Aceves will have thrown a combined 71 pitches in 6 1/3 innings in the last three days.
No matter. Given the chance, he'll probably be back in there once more with the season on the line.
"He has done it time and time again. He's so valuable doing what he's doing," manager Terry Francona said. "We thought about leaving him in, letting him run it out. But I think because he's so resilient, I think we'll have him, in fact, I know we'll have him tomorrow. Chances are, we'll probably need him."