Mitchell Robinson’s latest injury underscores Knicks’ Isaiah Hartenstein free agency dilemma

Mitchell Robinson’s latest health issue brings Isaiah Hartenstein’s future to the forefront, both for this season’s playoff run and the years ahead on Jalen Brunson’s shoulders.

Robinson, when healthy very early this season, emerged as an All-Defense candidate and the NBA’s top offensive rebounder. But he’s now missed the majority of two of the last three playoff runs with foot-area injuries. He’s sat roughly 40 percent of the regular-season games in the last four seasons.

Hartenstein, a revelation after taking Robinson’s starting spot this season, has proven more durable, even with that troublesome left Achilles. And the 26-year-old is heading into a free agency that he’s expecting will bear fruit.

“I know I’m getting paid regardless,” he said after the Sixers series.

How much is certainly of concern to the Knicks.

Unlike with other pending free agent OG Anunoby, the Knicks don’t hold Hartenstein’s full Bird Rights. They have his Early Bird Rights, which sets a restriction on how high their offer can go while still being over the cap (the Knicks will be over the cap).

In Hartenstein’s case, the max offer starts at roughly $16.1 million. There will be teams with enough cap space — the Pistons, Sixers, Jazz, Spurs, Thunder and Magic, for instance — to exceed that offer and potentially pry Hartenstein out of New York

But would Hartenstein command that much in the open market?

In March, ESPN front office insider and former longtime NBA executive Bobby Marks estimated Hartenstein’s free agency value at $13 million-$14 million per season — or roughly what Robinson will earn next season. Marks added that centers don’t get big money anymore but Hartenstein could benefit from a weak 2024 free agency class, with Brooklyn’s Nic Claxton and New Orleans’ Jonas Valanciunas at the top.

Of course, a strong playoffs — accompanied by a deep run — could boost Hartenstein’s value.

Heading into Wednesday’s Game 2 against the Pacers, he’s averaging 10.7 points in 27.7 minutes while flaunting a push shot/floater in the paint that developed into one of New York’s most consistent offensive weapons outside of Brunson’s isolation wonders.

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“It’s always something that’s part of my game, but maybe not as — I didn’t use it as much as I started using it when I went to the Clippers (for the 2021-22 season) because I was getting a lot of pocket passes and that was the easiest shot to take,” Hartenstein told The Post. “I don’t know how it became my shot but … I feel real comfortable with it. It’s like a layup at this point. I feel like it’s one of my most comfortable shots. It’s hard to block and easy to get in rhythm so it feels like it’s still giving guys spacing even if it’s not on the 3-point line.”

As with every other big decision for the Knicks, Hartenstein’s free agency isn’t in a vacuum. Anunoby and Precious Achiuwa are both headed into the market as well. Anunoby, who will have to decline a $20 million player option, is a priority and set for a huge payday. Achiuwa is restricted free agent — meaning the Knicks can match any offer — but won’t get as much as Hartenstein.

Marks also estimated to The Post in March that Achiuwa’s value is $8 million-$10 million per season. That was also before Achiuwa was sent to the bench following the returns of Anunoby and Robinson from injuries.

Re-signing all three would send the Knicks into the luxury tax, and that’s not a comfortable place under the new CBA with the roster-building restrictions.

They do have an inexpensive option as a backup center in Jericho Sims, who is earning just $2 million next season with the athleticism and defense that could blossom into a strong backup option.

But relying on the original starter, Robinson, is a tough sell considering the health history.

And that’s making the upcoming free agency of Hartenstein, the most reliable of the Knicks centers, more important.