That was fast.

Warriors assistant coach Luke Walton already has interviewed with several teams about their head-coaching vacancies, including the Knicks and Nets, according to multiple NBA sources. Walton pulled himself out of consideration for the Nets job and the team announced the hiring of Kenny Atkinson on Sunday.

The Post first reported Sunday afternoon Knicks president Phil Jackson already spoke with Walton in a phone interview.

Walton is considered a big long shot to take the Knicks job as he’s a West Coast product, having grown up in Southern California and played at Arizona.

A late report Sunday night stated Walton told the Knicks he’s not ready to continue talks at this time, but an NBA source said he hasn’t completely ruled it out.

Jackson put his own spin on the nature of the talks in a tweet Monday morning.

Walton agreed to speak to Jackson because of the “uniqueness” of working for the Zen Master, the source said.

The league source said Walton is a favorite to stay with the Warriors another season, but he isn’t close to deciding what to do.

“It’s going to be a long, deliberate process,” the source said. “What he has now is very difficult to re-create.”

To join Steve Kerr’s Golden State staff, Walton turned down Jackson’s offer to be one of Derek Fisher’s assistant two years ago. If the Lakers job opens up, Walton figures to be a top candidate there also.

Jackson also figures to speak to one of his former Lakers assistants, Brian Shaw.

NBA legend Bill Walton, Luke’s father, recently said his son should stick with the record-breaking defending champions, who just set an NBA regular-season record with a 73-win season. In filling in for Kerr as he recovered from offseason back surgery, Walton guided the Warriors to a 39-4 record to start the season.

“First of all, Luke doesn’t listen to me. He makes his own decisions,” Bill Walton said. “I always tell him the same thing: ‘Luke, it doesn’t ever get any better than what you have right now.’ I was part of three of the greatest teams ever — UCLA, Portland, the Celtics. I’ve been at the other end of the spectrum, too. There are opposite ends of every teeter-totter, so I tell him, ‘Money can’t buy what you have.’ Head coaching jobs, they’re open for a reason. Those reasons don’t exist in Golden State.”

The Post previously reported the Warriors would give Walton permission to talk to other teams as long as it doesn’t interfere with their playoff run.

Jackson said Thursday he would conduct a narrow coaching search confined to people he knows. Walton — who played in Los Angeles from 2003 to 2011, won two titles and played in four NBA Finals — is considered to have been one of Jackson’s favorite players while with the Lakers.

Walton and Kerr do not run the triangle offense in Golden State — just principles of it. Jackson insisted Thursday he still wanted to run a triangle-based system next season.

“I think Phil knows how much I know the triangle and love the triangle,’’ Walton told The Post last season about his assistant-coaching dalliance with the Knicks. “I thought it would’ve been a good fit. I had stayed in touch with Phil. He’s been a mentor and teacher to me in basketball and in life even before getting into coaching. We had a few conversations with him about coming to New York, joining Derek’s staff. I had a few phone calls with Fish. While I was doing that, I was in contact with Steve.”

Toward the end of Walton’s playing career, then-Lakers coach Jackson began inviting Walton to coaches meetings to lift his spirits.

“I was really into what they were doing, and I figured if I can’t play, I’d like to do this coaching thing,” Walton said earlier this season.

Interim coach Kurt Rambis still is in the mix for the Knicks’ permanent job, but for now, Jackson has a wandering eye. Jackson had said his search could take until July.

In Jackson’s recent biography, “Eleven Rings,” he praised Walton for his high basketball IQ and grasp of the triangle.

“He didn’t have a killer jumper, nor was he gifted at creating his own shots,” Jackson wrote. “But he loved moving the ball and playing the game the right way. He was also gifted at shifting the flow of the action from one side of the court to the other, a critical move in the triangle offense. Many coaches don’t place a high value on such skills, but I encouraged Luke to grow in that direction. Eventually, he blossomed into one of the best facilitators on the team.”

Ironically, when the Knicks were in Oakland, Rambis, who coached Walton in LA, took a dig at his playing style and withheld praise at the remarkable job he did filling in for Kerr.

“He just continued to perpetuate what was going on,” Rambis said in March. “It’s not like he changed anything. He continued to allow the team to play the way they’re playing and been successful with. It’s difficult to coach any team, even a good team. You got to keep them motivated and challenged. It’s tough as defending champions to meet that challenge night in and night out.

“Luke’s a good guy,” Rambis added. “Sometimes we wanted Luke to shoot the ball more than he did because he’s so unselfish and passes the basketball. But sometimes you got to shoot the ball to keep the defense honest and sometimes you not shooting is almost as bad as taking a turnover.”