NEW YORK -- Joba Chamberlain is likely out for a year and then some, and he doesn't even feel any pain.

The right-handed Yankees reliever was diagnosed with a complete tear of the medial collateral ligament in his right elbow on Thursday, making Tommy John surgery and a 10- to 14-month absence imminent. The oddity is that Chamberlain feels no pain, with the only physical indication for him that something was wrong coming on Tuesday, when he felt tightness.

That was a day after Chamberlain's last outing, Monday's 35-pitch effort in which he said his stuff wasn't there.

"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 Yankees' strict efforts to keep a young Chamberlain healthy early in his career were well publicized; guidelines about his pitch count and usage were dubbed the "Joba Rules." Chamberlain said he was briefly in tears when he heard Thursday's news upon undergoing an MRI exam for a second successive day.

"I was just trying to get out of there as soon as I could before I broke down," Chamberlain said of his reaction. "To be perfectly honest with you, for about the first 30 seconds, I said, 'This [stinks].' But after that, I just said a couple prayers and said, 'You know what? I'm going to be better for this.'"

The Yankees announced that Chamberlain was hurt to a lesser degree on Wednesday, before he went for the second MRI exam. He was placed on the 15-day disabled list and instructed to rest for 10-14 days because of a strained flexor tendon, a diagnosis that was made after a standard MRI exam. On Thursday, Chamberlain went for a dye-contrast MRI exam, and as the test is designed to do, it revealed more.

"In terms of a concern, [Chamberlain] wasn't on my radar for any concern. Period," general manager Brian Cashman said. "[Not] until [team doctor Christopher Ahmad] called me and said, 'Hey, I just want to give you a heads-up.' He said Joba came in early, which is unusual for him, which [was on] Tuesday, to get some treatment. 'As you know, he's been getting treatment on the road, but he's never come in that early. That's kind of a little bit of a red flag.'"

"[Ahmad] was shocked. I know Joba's still shocked."

The second MRI was set up immediately after the first one, Cashman said, primarily because a forearm injury was in play.

Chamberlain's test results will now be forwarded to Dr. James Andrews, and after the famed orthopedic surgeon's review, a final decision on whether to undergo the operation will be made. But Chamberlain and Cashman made that sound like a formality.

"That's why you always hear that dreaded forearm strain -- a lot of times, it does lead to a Tommy John issue," Cashman said. "I wouldn't really comment further on it until the dye-contrast MRI was done today because that would give us a real picture of what we were dealing with. ... His strength and stuff is there; it's not like there's something that we were expecting or dealing with. The MRI does not match up with any symptoms."

Chamberlain's absence leaves David Robertson as the Yankees' primary setup man. Robertson was supposed to play a support role in the bullpen coming into the year, but the Yankees' two biggest weapons in front of closer Mariano Rivera, Chamberlain and Rafael Soriano, are both hurt. Cashman said it was too early to know how Soriano was progressing from his own right elbow injury.

The Yankees will look internally for pitching help before going the trade route, although Cashman said a trade market had yet to emerge.

"The losses of a [Pedro] Feliciano or a [Damaso] Marte weren't as significant, even though they were significant losses because we had righties that really neutralized lefties, too," Cashman said of injuries to other relievers. "Whether [help] comes from promotions or acquisitions remains to be seen, but that's my responsibility."

Cashman noted it would be easier to acquire a right-handed reliever than a starter and that the club has some ideas about whom it could promote from within. Not included in that mix, though, are prospects Dellin Betances and Manny Banuelos. Cashman also nixed putting Phil Hughes back in the bullpen, and the club revealed that Mark Prior -- currently on the Minor League DL with an abdominal strain and a groin strain -- has been tested for a sports hernia, the results of which were negative.

Chamberlain went 2-0 with a 2.83 ERA in 28 2/3 innings and 27 appearances this season, starting off well after finishing with an ERA over 4.00 in each of the past two seasons. Chamberlain's father is often a presence at Yankee Stadium, and Harlan Chamberlain said on the field on Thursday that his son would come back improved.

"He's coming back stronger," Harlan said. "What you saw in '07 and '08 is probably what you're going to see again, and more. He'll have five seasons under his belt. He's 25 -- his best years in baseball are yet to come."

Chamberlain did show up to Spring Training overweight, but his arm was healthy, according to Cashman. Asked whether he would have proceeded with different "Joba Rules," Cashman noted that the restrictions then and today hold true, unchanged, as part of the Yankees' player development program. Simply, most players don't make the Majors as early as Chamberlain did, which is what made the rules so widely attributed to him.

"These guys are like thoroughbreds," Cashman said. "That's why you try to get as educated and you try to have a structured system, but it doesn't guarantee anything and no one has ever guaranteed anything."