FORT MYERS, Fla. -- If in a bit of an underrated way, Alfredo Aceves helped the Yankees win the World Series two years ago. But his loyalty is now with the other side of baseball's most storied rivalry.

The Yankees, though appreciative of what Aceves did out of the bullpen to help their 2009 team, weren't confident he could stay healthy. They gave him a non-tender pink slip in December, and the Red Sox swooped in and signed him just before Spring Training started.

On Monday night at City of Palms Park, Aceves faced his former team for the first time.

"It was a good day," said Aceves, who started and pitched three innings in Boston's 2-1 victory. "We played against the Yankees and everyone was excited to see this match, you know? Also, I was excited, too. Fortunately, they only scored one run."

The Red Sox think they could be the ones to benefit from the overly problematic back condition Aceves had last year, when he was able to pitch just 10 times for the Yankees.

"I think we probably caught a little bit of a break," said manager Terry Francona. "Because of his injury situation, we got a chance to get him where normally you wouldn't, because he'd be on a Major League contract long gone before we were able to get him."

Yankees general manager Brian Cashman expresses no remorse for his decision to part ways with the righty. It was purely business.

"He's got a back condition and we could not get him healthy, and I'll leave it at that," Cashman said. "It doesn't mean he wasn't pitching for a period of time in his rehabs, but we gave him three epidurals [and] couldn't get him on the mound without breaking down. So he's got a back condition. ... We're obviously happy to hear for him -- not for the Red Sox -- that's he's been able to get a back program going that's put him in a position that it's not a condition for him at this stage."

If Aceves feels any bitterness toward the Yankees for not thinking he could get healthy again, he isn't expressing it.

"It's not in my hands to make that decision," Aceves said. "It's not in my hands. We do the best we can do out there on the field. That decision is not in our hands."

Does the 29-year-old Aceves believe his back is in better condition than Cashman and the Yankees suspected?

"I don't know. I feel great. I feel 100 percent," Aceves said. "It's getting better. In Spring Training, it's getting better with the days."

If Aceves can keep that back healthy, perhaps he can be as valuable to the Red Sox as he was for the Yankees in 2009, when he ate some 84 innings out of the bullpen, posting a 3.54 ERA.

"It's unfortunate that he had so many back issues last year," said Yankees manager Joe Girardi. "I thought we missed him a lot. He was a guy that could bridge us from the fourth to the seventh inning. And I wish him the best of luck. He was great for us."

There were glimpses of what Aceves could be for the Red Sox on Monday. Over his three-inning stint, he allowed three hits and a run, walking one and striking out one.

"I thought all our pitchers did a good job, starting out with Alfredo," said Francona. "He threw strikes, worked quick. He's animated out there, he's enthusiastic, but he has three pitches he throws for strikes."

Before he pitched against his old teammates, Aceves spoke with them.

"Yeah, like an hour and 30 minutes before the game, I went out there just to say hello to my teammates and the coaches and stuff," said Aceves. "Everybody, everybody who was my teammate I spoke to. I spent three years on the Yankees, so I just [went] out there to say hello before I pitched."

With the reunion over, Aceves will continue in his quest to make Boston's Opening Day roster. He does have Minor League options left.

"That's not in my hands, that decision," Aceves said. "I come here and work hard. I like to play baseball. What can I say? What else can I say? We're trying to have a good Spring Training, a great Spring Training, and work hard and we'll see what happens. We're preparing for the season. It's a long season."