Chamberlain was prepared as a starting pitcher during Spring Training, a role the Yankees envision that he will eventually fill at the Major League level.
The Yankees' area of need is greater in relief, where Chamberlain will slot in behind closer Mariano Rivera and share setup duties with veterans Kyle Farnsworth and LaTroy Hawkins.
"Right now to be on the back end of things, I'm going to be there with Farnsie, LaTroy and Mo," Chamberlain said. "I think that's going to be something that helps us now. It's about winning games. It's not about Joba Chamberlain, it's about winning [World Series] No. 27."
Yankees manager Joe Girardi, general manager Brian Cashman and pitching coach Dave Eiland delivered the news to Chamberlain at Legends Field on Wednesday afternoon, before the club traveled to Bradenton, Fla., for an exhibition game against the Pirates. Last season's "Joba Rules," which gained so much speculation and notoriety, will not be re-enacted to restrict Chamberlain's use.
"It's a combination of things -- his innings, his success and where we feel he fits best now," Girardi said. "It's just something we decided as an organization."
Chamberlain compiled a 0.38 ERA in 19 appearances after joining the Yankees in early August, hitting his first major speed bump when he was the losing pitcher in Game 2 of the American League Division Series in Cleveland.
The Yankees believe Chamberlain can be similarly dominant as he serves an interchangeable role with Farnsworth and Hawkins. The fans, however, may be a different story -- as Girardi said on Wednesday, "the expectations are off the chart."
"I think we were all kind of expecting it going in," teammate Phil Hughes said. "He showed us last year that he can do a great job in that role. I've seen him in the Minor Leagues and a little bit starting this year, and he's got four plus pitches, so he can start. It's definitely a good feeling having a guy down there that can even go two or three innings."
Chamberlain said that his success in 2007 is not nearly as important as how he will handle situations in '08.
"You've got to take it a day at a time," said Chamberlain, who is 1-0 with a 6.14 ERA in 7 1/3 Grapefruit League innings. "I'm still trying to get outs, and I've got a lot left to prove in this game.
"I know that I'm going to take my licks and I'm going to take my lumps. I have to ask questions and learn as much as I can in the role that I'm in."
Chamberlain will see his first action out of the bullpen on Thursday against the Blue Jays in Dunedin, Fla. The Yankees plan to bring him back in relief on Saturday, and he will pitch in back-to-back games by the end of the month.
"It's great, not only to know, but just to get your routine down," Chamberlain said. "The arm is in shape, and that's the easiest part now."