Mark Teixeira’s 2013 season is over almost before it began, with the first baseman set to go under the knife early next week to repair a torn tendon sheath in his right wrist.

“The final point was Sunday when after a week, the cortisone shot didn’t work,” Teixeira said before the Yankees’ 8-5 loss to the Rangers last night. “I usually respond very well to cortisone shots. I’ve had a dozen or more in my career, but when it didn’t work and I wasn’t getting any better, I knew it was probably going to be bad news.”

He finally got that news yesterday after a group of doctors, including team physician Christopher Ahmad, reviewed an MRI exam with dye contrast and concluded the injury hadn’t healed properly and recommended surgery.

The Yankees had hoped rest would be enough to keep Teixeira on the field after he initially suffered the injury preparing for the WBC on March 5. But after just 15 games back with the Yankees, Teixeira was pulled from a June 15 game in Anaheim and received the cortisone shot the following day.

The shot proved ineffective and the soreness persisted.

Following the procedure, Teixeira will have four or five months of rest and rehab and is expected to be fully healed in six months.

“This isn’t one of those degenerative conditions where you need to protect it the rest of your career,” he said. “It’s a torn tendon sheath and once it’s fixed, I should be OK.”

Toronto outfielder Jose Bautista underwent a similar procedure Sept. 4 and was back in time for spring training.

That still leaves the Yankees in need of a right-handed first baseman to fill in for Lyle Overbay.

“If something declares itself as an opportunity that makes sense — that we can acquire at a price that makes sense to us — obviously we’ll have to look at it,” general manager Brian Cashman said.

There is not a ton available, especially for what the Yankees could offer.

Potential targets could include Michael Young or John Mayberry from the Phillies, but Philadelphia hasn’t given up on its season yet, so they may not be available now. The Rangers’ Jeff Baker, whom the Yankees had some interest in during the offseason, has been productive in limited chances this season. San Diego’s Kyle Blanks is another possibility.

As team president Randy Levine said Tuesday, since Teixeira returned from the original injury — albeit briefly — the Yankees are responsible for the remainder of his salary this season, although up to 80 percent of that could be covered by insurance.

“It’s a big blow,” CC Sabathia said. “We’ve dealt with injuries all year. It is unbelievable. I feel like if it was any other team, it would crumble. But we have the guys in here to get the job done.”