Yankees reliever Joba Chamberlain has a torn ligament in his right elbow, a startling injury that's likely to require Tommy John surgery and end his season.

A test yesterday morning revealed the tear. It came a day after New York put Chamberlain on the 15-day disabled list with a stiff elbow, the latest setback for the back of the Yankees' bullpen.

But Chamberlain and the Yankees said they had no idea the injury was so severe when he went for the additional checkup. Chamberlain said he was "kind of in shock" and shed a few tears at the diagnosis, and said he didn't know how or when he hurt himself.

"I know I can get surgery and get it fixed," he said.

The Yankees said they would send reports on Chamberlain to noted orthopedist Dr. James Andrews. Chamberlain, Andrews and the Yankees plan to discuss the condition before deciding on a course of action.

Said Yankees manager Joe Girardi: "My guess is he's going to have to have the surgery."

The 25-year-old Chamberlain is 2-0 with a 2.83 ERA in 27 games. The hard-throwing righty has been a key member of the Yankees' staff for several years, and has pitched in a variety of roles.

The Yankees already were missing setup man Rafael Soriano, out with inflammation in his right elbow.

Girardi said David Robertson would inherit the role as setup man for closer Mariano Rivera.

Chamberlain last pitched Sunday against the Los Angeles Angels, his eighth straight scoreless appearance. His velocity has been in the mid-90s mph and he'd been able to throw effective breaking balls. He said he played long toss on Tuesday without any pain.

Chamberlain had been getting regular treatment on the area where his forearm and elbow met for nearly 2 weeks. He said his elbow felt fine when he pitched, but stiffened after games. An MRI on Wednesday showed a strained flexor muscle and he was put on the DL retroactive to June 6.

"He wasn't on my radar for any concern," general manager Brian Cashman said.

Noteworthy

* The Kansas City Royals are calling up third baseman Mike Moustakas from Triple A Omaha and the long-awaited first-round draft pick of 2007 is expected to make his debut tonight at the Los Angeles Angels. Moustakas was hitting .356 in his last 10 games. For the season, he was averaging .287 with 10 home runs and 44 RBI.

* Boston Red Sox second baseman Dustin Pedroia has a bone bruise on his right kneecap and is expected to rejoin the team for tonight's game at Toronto.

In games yesterday:

* At Kansas City, Jeff Francoeur drove in two runs, helping Luke Hochevar win for the first time in seven starts, and the Royals survived Joakim Soria's shaky ninth to beat the Toronto Blue Jays, 3-2.

Soria, reclaiming the closer role he lost May 30 after back-to-back blown saves, loaded the bases in the ninth but got his eighth save in 13 opportunities.

Hochevar (4-6) allowed two runs in the fourth but nothing else in seven innings. The righthander gave up six hits, walked three and struck out three for his first win in seven starts since May 1.

* At Detroit, Alex Avila hit two triples and scored a run, Brennan Boesch hit a two-run homer, and Justin Verlander (7-3) pitched eight strong innings as the Tigers beat the Seattle Mariners, 4-1 .

* At Chicago, Adam Dunn and Paul Konerko each hit two-run homers to lead the White Sox to a 9-5 win over the Oakland Athletics, who were playing their first game under interim manager Bob Melvin.

The Athletics fired Bob Gernen after losing nine straight games to fall to 27-36 this season. Geren posted a 334-376 over four-plus innings.

* At Minneapolis, Alexi Casilla's run-scoring single in the ninth led the Minnesota Twins to a 5-4 win over the Texas Rangers.