DETROIT -- Upbeat by nature, Red Sox closer Andrew Bailey is already that way again, just two days after undergoing right thumb surgery that is expected to sideline him until at least the All-Star break.

Sure, Bailey was upset at the bad timing of his torn UCL injury, so he let those emotions go through him for a short stretch. But he knew that if he stayed that way, it would only be detrimental to his rehab.

"It's extremely frustrating. I went through the day of 'Woe is me' and then the next day of being [angry], and the frustration," Bailey said in a Friday afternoon conference call. "You get back to the same point of dealing with it and moving forward, and being mentally tough enough to overcome it and do the rehab and work hard to get back. That's what I have to do.

"Obviously it stinks, and everyone knows that. It's just part of the game. It's frustrating. But I've just got to move forward, and when I am healthy [enough] to get back out there, [I need to] do my job and everything will be OK."

When Spring Training started, Bailey envisioned helping the Red Sox win the World Series. His thumb might have a cast on it, but his goal hasn't changed.

"I know that I'll be better for it in the long run and come back as good as new, and be ready to help this team, as soon as the body allows [me], to achieve our goals of winning the World Series," Bailey said. "That's what I'm looking forward to do. Until that point in time, I'm just trying to stay focused. And whether it's answering questions from some of the guys in the bullpen, or whatever it is -- watching video, trying to help them any way I can -- that's what I'll be doing. [I'll be] trying to be a good teammate and trying to help them as much as I can, [despite] not being on the field."

Bailey, who had his surgery on Wednesday, was in transit back to Boston during Thursday's Opening Day loss in Detroit. It was a game that was lost by the back end of the bullpen -- the kind of game he could have helped the Red Sox to win.

"There's a lot of good arms down there in the bullpen, and those guys are going to have a great year. I'm looking forward to joining them at some point and time, and hopefully soon," Bailey said. "They'll be fine. It's just the way things happened, and when I got injured -- very late [in camp] -- and [there have been] a lot of questions the last couple of days. It's kind of all thrown in a jumble at the end.

"Those guys will get their roles defined and guys will pitch themselves into certain situations. ... It will be good. For me, [I'm] just kind of staying focused on my rehab and getting back out there as soon as I can."

Though he didn't think anything of it at the time, Bailey is now sure his injury had to be caused by the collision he had covering first base on March 21 against the Pirates in Bradenton, Fla.

"Basically what happened was that Pittsburgh game, I got up on it wrong, awkwardly, or jammed it on the runner," Bailey said. "[I was] just trying to be an athlete covering first base, and it's just one of those freak things that stinks. I really didn't think anything of it for a couple of days. It wasn't until about two days later, just kind of everyday activities -- whether that's where the whole shampoo bottle kind of came out -- or just kind of [feeling it] in everyday activities."

Unfortunately for Bailey, he has dealt with prolonged injuries before, both in the Minors and Majors.

"Hopefully all these injuries are behind me, and I'll just take care of this one and just keep looking forward," Bailey said. "That's all I can do, is just keep looking forward. That's all I can do is keep pushing forward and take care of business and get back out there and be ready to rock when the body is ready to go."

Until the Red Sox can hold leads consistently in the late innings, there figures to be constant questions about how the bullpen should line up without Bailey. On Opening Day, manager Bobby Valentine started the bottom of the ninth inning in a tie game with setup man Mark Melancon. With two on and one out, he went to Alfredo Aceves.

"That's not really my decision," Bailey said. "That's the manager's decision. Bullpens always figure themselves out. Roles are always changing, usually. There's a lot of good arms down in that 'pen. They'll figure themselves out. Bobby said Aceves will be the closer right now, and [Aceves has] some great stuff.

"I know Mark's got some experience, and a lot of guys down there will be fine in that role. The bullpen will be fine. They'll be all right. They'll hold it down until I get back and [am] able to help them out. I'm just focused on myself, and those are Bobby's decisions."