GREENBURGH, N.Y. — Carmelo Anthony will undergo season-ending surgery on his left knee and could miss four to six months, according to Knicks president Phil Jackson.

The team said on Wednesday that Anthony will undergo a procedure that “includes a left knee patella tendon debridement and repair.”

Jackson said he did not want to go into detail about what type of surgery Anthony is undergoing but that he likely will be sidelined several months before returning to the court.

“What we’re finding out from the medical is on court, it could be four to six months,” Jackson said in a press conference today at the Knicks’ practice facility. “We can’t put it at a timetable until after the surgery. But that’s what they’re saying. They say it can be anywhere between four to six months for Carmelo to be back on the floor.”

“But we’re really confident he’ll heal well and he’ll be fine,” Jackson later added.

The Knicks’ leading scorer and franchise player has been dealing with pain in his left knee for months and Jackson called it “a long-term thing that just is a continual aggravation that was going on.” Anthony previously underwent an arthroscopic procedure to his left knee in 2011.

“It wasn’t something that was sudden from [last] summer’s activity,” Jackson said.

Jackson said he and Anthony met when the team played in London in mid-January to discuss having the surgery “sooner than later” to start the rehab process.

Anthony played in Sunday’s All-Star Game at Madison Square Garden, logging 30 minutes and finishing with 14 points on 6-of-20 shooting for the Eastern Conference.

“We know that it was the type of surgery that is corrective obviously and that he could play on it,” Jackson said. “He could tweak it as he has a number of times this year and because of some discomfort and inability to play at time, so we felt comfortable with him playing in the All-Star Game.”

Owning the worst record in the league at 10-43 and in full rebuilding mode, the Knicks didn’t have much to gain by keeping Anthony active the remainder of the season.

When asked how it was like to coach Anthony, head coach Derek Fisher said, “This is not a funeral.”

With Anthony now done for the season, the post All-Star portion of the Knicks’ season begins with a clear eye on this summer and rebuilding the team. Having traded the likes of J.R. Smith and Iman Shumpert and reaching a buyout agreement with Amar’e Stoudemire, the Knicks will evaluate their remaining talent for the remainder of the season while Jackson scouts college talent with a high first-round draft pick in his pocket.

“The dance floor is now open,” Fisher said of the opportunity that current Knicks players have.

Jackson said the Knicks are keeping an eye on impending summer free agents around the league that could be moved before Thursday’s trading deadline.

“We want to be in the conversation,” Jackson said. “I don’t know how serious we can about it. But we’d like to be in the conversation. So we’re interested. We’re staying open-minded.”

Armed with ample cap space to lure free agents and a lottery draft pick, Jackson has the Knicks situated to continue a complete overhaul this summer.

“I am not happy,” Jackson said of where the Knicks are. “But it is what it is. And that’s what you have to accept, that this is what we got now.”

“We are a little disappointed in how the outcome came,” Jackson added. “But that all being said, we would have been in this position come April 15 anyway — season’s over, we knew we were going to build.”

And he believes New York, and a healthy Anthony, will be able to attract talent.

“Why wouldn’t it be?” Jackson said. “… I can’t imagine not wanting to play in New York because of the fans and the arena. The participation the fans have in basketball and their desire for our team, it’s just a fact of the way this game is structured in this city that people know the game, like the game and pay attention to it.”