Joba Chamberlain will have Tommy John surgery next Thursday which will end the season for the Yankees reliever.

Chamberlain tried to stay positive Friday as he stared at a rehabilitation process that will keep him out for at least the next 12 to 16 months.

“This is a surgery that a lot of people have,” Chamberlain said. “People understand that you can come back from this. Surgery is just one-third of it. The rehab is two-thirds of what’s going on. That’s an important part, and the most important part.”

The Yankees sent Chamberlain’s test results to Dr. James Andrews to get another opinion on what their own doctors saw, but they fully expected to hear he would need the ligament replacement surgery, which will be performed in Pensacola, Fla.

“I was pretty settled he was going to have surgery,” Joe Girardi said. “I’ve never seen anybody but R.A. Dickey that’s pitched without [the ligament]. I was pretty convinced that he was going to have surgery.”

A dye-contrast MRI exam Thursday on Chamberlain’s right arm revealed the damage that requires the ligament replacement. Chamberlain’s agents requested the MRI exam results be sent to Andrews.