The longest-tenured Knick probably won’t get a chance at an NBA title repeat.

Mitchell Robinson is unlikely to return to the Knicks next season, a source told The Post’s Stefan Bondy on Thursday night.

Robinson is an unrestricted free agent, and with Knicks owner James Dolan making clear he is not willing to go into the second apron, it was always going to be questionable whether the big man would be back in New York.

Dolan said last week during an appearance on “The Carton Show” on WFAN that going into the second apron — due to its restrictive nature in free agency — would not be an option for the newest NBA champs.

“There’s certain things in the NBA that you’d have to be suicidal to do. One of them is the second apron. Cannot go into the second apron,” Dolan said. “I’ll write as big of a check as possible, but I can’t write a check that goes into the second apron.”

The second-apron strategy was apparent in the NBA draft this week when the Knicks traded out of the first round and thus did not have to pay a guaranteed contract.

The Knicks will still have other free agent questions to face, including from Landry Shamet, who is also an unrestricted free agent. Earlier this week, The Post reported the Knicks are nearing a multiyear deal worth more than $10 million for Mohamed Diawara to return.

If this is indeed the end for Robinson in the Big Apple, it ends a run that started in 2018 when he was taken as a second-round pick out of Western Kentucky.

He was a valuable rotation player in the regular season this year by averaging 8.8 rebounds in 19.6 minutes across 60 games.

Robinson, though, averaged about six minutes less during the playoffs and continued to struggle from the free-throw line (29.3 percent) as teams tried to employ the Hack-a-Mitch strategy.

And while he mysteriously broke a bone in his right hand on the eve of the NBA Finals, he played a pivotal role in the clincher with 10 rebounds, including an offensive board with 22 seconds remaining that helped the Knicks retain control of the ball before OG Anunoby hit 1 of 2 free throws to ice away the game.