But three months into the campaign, Aceves may have stepped up as the best late-inning option. The Mexican League product has already earned four victories in relief since being recalled, helping stabilize a bullpen that has been ravaged by injuries.
"Ace has been a big part of that, he really has," manager Joe Girardi said. "Some of the innings he's given us have allowed us to win games and ... he's got four wins, so that tells you what he's been able to do for us."
The most recent of those came on Sunday, when Aceves slammed the door on the Rays with two innings of scoreless relief. He struck out the final four batters he faced in New York's 4-3 victory, helping to set up Mariano Rivera's 13th save.
"I believe this team is special," Aceves said. "We're doing our jobs, everybody. We're having a good time, and we're in first place. I feel great. I feel happy to be here with this team."
Aceves has had to adjust on the fly, entering Spring Training in a competition for a long-relief role that was eventually scrapped in favor of carrying Jonathan Albaladejo as an extra bullpen arm.
Aceves was 2-0 with a 3.80 ERA in four starts at Triple-A Scranton/Wilkes-Barre at the time of his recall on May 4. Though the bullpen role is somewhat unfamiliar, it certainly appears to have proven enjoyable for Aceves, who is 4-1 with a 2.70 ERA in 23 1/3 innings, walking five and striking out 24.
"Of course," he said. "I enjoy playing baseball, wherever it is. I feel great, and I feel strong. It's not my decision to keep [pitching in relief], but whatever situation or wherever they'd use me, it works. We're trying to do our best."
After Sunday's game, Girardi said that the nice part about having a pitcher like Aceves on the staff is that "he has weapons for all different types of hitters."
That has proven especially comforting as the Yankees wait for their intended setup men, Brian Bruney and Damaso Marte, to return from the disabled list. Aceves has also impressed Girardi and the Yankees' coaching staff with a certain resiliency.
"We've used him back-to-back before, so he has shown that ability," Girardi said. "I think Ace would take the ball every day if we gave it to him. That's the type of guy he is. But we do need to protect him, and we try to protect him by giving him normal days off when we can."
Aceves has been able to take some energy from all corners of the clubhouse, not just the pitching staff, and he believes that the Yankees have become a closer team during the month-plus he has been in the big leagues.
"We're trying to do our best. Everyone is fighting," he said. "If I see A-Rod fighting in his at-bat, it ... gives you power to do your work."
Bryan Hoch is a reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.