TAMPA -- Joba Chamberlain's comeback was dealt a serious blow Thursday when he suffered what the Yankees say is an open dislocation of his right ankle during an accident at a play area with his young son.

Chamberlain, already on the comeback trail from Tommy John ligament transfer surgery, underwent surgery Thursday night and will remain in a Tampa hospital for several days. General manager Brian Cashman termed it a "significant injury" but had few other details. He could not answer the question of whether or not it will sideline Chamberlain for the season, or even if it is a career-threatening injury.


"I can't tell you a time frame," said Cashman, who planned to visit Chamberlain in the hospital later Friday. "But obviously it's a significant injury. ... I can't tell you anything more than something very unfortunate happened late yesterday afternoon."

The Yankees learned of the accident shortly before their game against Boston in Fort Myers, Fla., on Thursday afternoon. Chamberlain's rehabilitation from elbow surgery had been going well. Last month, he threw from a mound for the first time since last summer's surgery.

"From the baseball stuff, he was doing great," Cashman said.

Entering his sixth major-league season, Chamberlain is scheduled to make $1.675 million this season, but he is on a non-guaranteed contract.

Reports that the Yankees had, according to sources, were that the ankle was twisted and that it was not a compound fracture. Nevertheless, with the dislocation, bone was said to be protruding through the skin and there was lots of blood. Chamberlain had one surgery Thursday night, and was having an MRI exam and a CAT SCAN on Friday morning before doctors decided what to do next.

A source close to the Yankees said a New York Daily News report that Chamberlain lost a life-threatening amount of blood was "news to us."

Chamberlain last pitched last June 5 before shutting it down for the 2011 season with the elbow injury. Before that, Chamberlain burst onto the scene dramatically as a 21-year-old rookie in 2007, pitching in 19 games, compiling a 0.38 ERA and landing a key role out of the Yankees' bullpen in the late innings.

His most well-known appearance, of course, was in Cleveland during the playoffs that season when a swarm of midges swept into Jacobs Field and covered Chamberlain as he attempted to pitch to the Indians during Game 2.

The Yankees intended to convert him to a starter and, as such, famously applied what became known as the "Joba Rules" to him in an effort to protect the health of one of their brightest young prospects.

Even so, his elbow gave out last summer. And now this ankle injury, suffered while with his son Karter, 5, threatens to completely derail what once was an incredibly promising career.

"There are places out there you can go, usually you're going with your children, and it's just basically a lot of gymnastics stuff," said Cashman, who thought the injury might have occurred on a trampoline. "That's what it sounds like, that is a loose description."

Cashman said manager Joe Girardi visited Chamberlain in the hospital at 7:30 a.m. Friday on his way to Legends Field. The GM was waiting until Chamberlain's MRI tests were finished before going to see him.

"He's in very good hands," Cashman said. "He's a healer. He's a tough guy. But at the same time, because he's part of our family, I'm worried about him. I can't imagine when you're sitting over there trying to do what you love as a professional baseball player, he's obviously been forced to sit out because of Tommy John surgery, and now something like this happens.

"A lot of things must be running through his mind. I just say a prayer for him, and we're here to help him to the best of our abilities. ... We'll wrap our arms around him and make sure he's getting the best care."

One concern at this point is whether or not this could be a career-ending injury.

"I couldn't say," Cashman said. "I'd like to say no. My heart and my gut tell me no. But at the same time I don't want to spew information I'm not [yet] in position to talk about."