Joba Chamberlain could be lost for the season after suffering a gruesome ankle injury Thursday that Yankees general manager Brian Cashman called "very significant."

The right-handed pitcher had surgery Thursday at St. Joseph's Hospital and will remain there for at least the next few days after undergoing an MRI exam and CT scan yesterday to determine the severity of the injury — which Cashman described as an open dislocation of the right ankle, meaning the bone broke through the skin.

The accident occurred while Chamberlain, 26, played with his five-year-old son, Karter, at a children's play place. Karter was not injured.

Cashman refused to put a timetable on Chamberlain's return and said of the injury potentially ending Chamberlain's career: "I'm not in a position to say," adding later, "I'd like to say no. My heart and my gut tells me no."

Though Chamberlain lost a considerable amount of blood and paramedics were called to the scene, both a Yankees source and the pitcher's agent denied that his life was ever in danger.

"There was no life-threatening loss of blood," Jim Murray, Chamberlain's agent, said.

Chamberlain's father, Harlan, told The Post reports that his son's life was in danger were untrue.

"That's [B.S.]," he said.

As for how the injury happened, Cashman said, "I believe it was a trampoline. Whether it was a trampoline specifically [I don't know]. ... There are places out there you can go with your children and it's just basically a lot of gymnastic stuff. That is a loose description because I'm hearing this third-hand.''