NEW YORK -- Just when the Yankees get Joba Chamberlain into a nice, stable, productive role, the bottom falls out of the whole scenario.

Here is Chamberlain, rolling along in a setup role, not having allowed a run in his last eight appearances. He has some right elbow discomfort, but nobody thinks it is a big deal, since he was still throwing his fastball in the mid-90s during the Yankees' recent West Coast trip and throwing his breaking ball with no ill effects.

On Wednesday, he goes on the disabled list with what is reported as a strained flexor muscle, a relatively minor injury. And then on Thursday, a second, more complex MRI exam reveals a torn ligament in his right elbow. Goodbye, 2011 season. Hello, Tommy John surgery.

This was a turn of events that was equally mystifying and dismaying for the Yankees. The usual signs of this ligament damage, like a notable loss of velocity, were simply not present.

"He doesn't have the symptoms," Yankees manager Joe Girardi said, more than once.

"I have no pain," Chamberlain said. "You could ask me to do anything. Just as far as being here, sitting here, [there's nothing]. A lot of guys who have had it feel a pop or certain thing -- it's hard to open doors, it's hard to do certain things. Nothing bothers me. That's what is really surprising for me.

"You're going to have to cut my arm off to stop me from pitching. But on the other hand, you have to realize this is your career. At 25, I'm still fairly young."

The "Joba Rules," which limited Chamberlain's innings in the formative stage of his career, were formulated as a way of protecting this career. The Yankees have gone to great lengths to carefully nurture the right-hander's career, and the payoff was a torn elbow ligament.

"We err on the side of caution [with pitchers]," Girardi said. "We try to protect them. We try to prolong their careers."

The Yankees' immediate problem is the bullpen. It should have been a source of stability, but it is now a place, Mariano Rivera aside, where questions will be raised. Rafael Soriano, coming off the finest season of his career and brought in at great expense as a setup man, is on the shelf with his own right elbow inflammation. Pedro Feliciano, a proven lefty situational pitcher, is out with a rotator cuff strain. And now, Chamberlain, who was establishing himself as a reliable setup man in front of Rivera, is out with what has become the classic elbow injury of contemporary pitching.

This was a franchise whose organizational plan included Chamberlain and Phil Hughes at the core of its pitching future. Hughes, of course, is out with right shoulder inflammation.

Nothing that happened on Thursday night -- or more to the point, early Friday morning -- did anything to lift the Yankees' spirits. After a three-hour, 27-minute rain delay and six innings' worth of a top-shelf pitchers' duel between CC Sabathia and Josh Beckett, the Red Sox broke the contest open with a seven-run, eight-hit barrage off Sabathia and his successor, David Robertson.

The resulting 8-3 Boston victory gave the Red Sox a 6-0 record at Yankee Stadium this season and an 8-1 record overall against the Yankees. There did not appear to be a silver lining anywhere near this particular cloud.

What does it all mean? In a word: Ouch.

The chances of the Yankees simply purchasing their way out of this bullpen issue are, for the moment, not supported by reality. There is a shortage of Major League-caliber relievers, and at this point in the season, the vast majority of teams hopefully consider themselves still in postseason contention. Relievers of the front rank are rarely available at this stage.

"We've lost some pretty good guys," Girardi said. "Some kids are going to have to step up for us."

That's the test sometimes. In contemporary baseball, pitching depth may need to go roughly 20 deep. The 12 people on an Opening Day pitching staff may be just the beginning.

For Joba Chamberlain's part of the Yankees' saga, maybe the expectations for the second phase of his career will be a little more lifelike than those for the first phase.

On the strength of 24 Major League innings in 2007, a larger-than-life legend was created around Chamberlain. These were 24 impressive innings, but they were still just a fractional portion of a season. And yet, in the wake of this brief big league exposure, a debate was formed along the lines of whether Chamberlain should be a perennial 20-game winner as a starter or the logical successor to Rivera as a closer.

When it came to pass that Chamberlain didn't quite measure up to either standard, he was judged not on his own merits but on the hype that his first 24 innings had generated. He was, in that sense, a victim of that hype. But he does not have to become a permanent victim. In the next phase of his career, the post-surgical phase, perhaps he can succeed on his own terms.

In the meantime, between Joba's elbow and the Red Sox, the operative Yankees word at the moment is still ouch.