It’s a start.

The Knicks made contact Friday with the agent for Frank Vogel, but have not yet requested an interview, according to two NBA sources.

According to one source, Knicks general manager Steve Mills did his due diligence in contacting Vogel’s reps. The source said Phil Jackson has not made a decision on how to proceed. The key to the exploratory phone call was finding out whether Vogel would have interest in the job, triangle offense and all — and it seems he does.

“I think the Knicks wanted to see where Frank’s head is at,” the source said.

Vogel, the winningest coach in the Pacers’ NBA history, responded with a “no comment” in a text message when contacted by The Post about his situation.

Meanwhile, the consensus around the league remained overwhelmingly positive toward Vogel. But one opposing executive raised an interesting point and waved off the notion of Jackson’s beloved triangle being a detriment.

“Frank Vogel is a very, very good coach,” the executive said. “Now to me — and I am speaking as an outsider — the problem is not about coaches or systems but continuity. They have a new cast of characters every year. How is anyone going to learn any system if the players are always changing?”

Jackson is on a road trip to his Montana lake house. A source told The Post on Wednesday the Knicks president wants to take some time away to think things over.

The Pacers announced Thursday they would not retain Vogel, but Jackson’s Western getaway was planned well before Vogel’s job was known to be in jeopardy. Vogel worked five-plus seasons for the Pacers, making the Eastern Conference finals twice, but the club got bounced out in the first round this season by the Raptors in seven games.

The Rockets also reportedly have expressed interest in Vogel.

Pacers president Larry Bird wants Indiana to jack up its offense, and Vogel — who was raised in Wildwood, N.J. — is known more as a defensive coach. Vogel has no experience running the triangle, but has some Jackson connections. He hired Brian Shaw as his Pacers associate coach because he wanted to learn from a Zen Master disciple.

Jackson has a close-knit circle, but has worked with Vogel, who was the Lakers’ advance scout in 2006. Vogel has said he and Jackson only had one conversation during that season since the advance scout usually is away from the team.

Sources familiar with Jackson’s thinking said they feel he’s leaning toward re-upping with interim coach Kurt Rambis because he wants to take the triangle a step further. However, there’s a plausible scenario in which Vogel could become head coach with Rambis sliding over as offensive coordinator.

Jackson has also interviewed former Cavaliers coach David Blatt and, as first reported by The Post, spoke with Warriors assistant Luke Walton, who instead accepted the Lakers’ head-coaching job. Blatt, a longtime friend who shared the Princeton backcourt with Mills, has told confidants his sit-down with the Knicks in New York was not a courtesy interview and felt he had a shot.

There were plenty of questions Thursday over whether the Knicks would even call Vogel, and neither side seemed in a hurry to get things moving following Bird’s press conference. Vogel, who wanted to stay with Indiana, had asked Bird if they could just meet to talk things over before making the public announcement that his expiring contract would not be renewed. That’s not a sign of a coach looking to leave the Midwest.

On Thursday, Vogel’s agent, Lonnie Cooper, told The Post: “We are taking the day to reflect. It’s a process.’’