Isaiah Hartenstein demonstrated what the role could be at its peak. The job as the Knicks’ backup center — at the time occupying the spot behind an injury-prone Mitchell Robinson on the depth chart — could serve as a launchpad to an $87 million deal in free agency. To pricing out of the Knicks’ maximum offer due to the early Bird rights.

Thunder center Isaiah Hartenstein signed a three-year, $87 million deal over the summer after two seasons with the New York Knicks. However, he still follows his former team, which he admitted to rooting for during the Knicks’ Christmas Day matchup against the San Antonio Spurs.

It was a happy return to Manhattan for Isaiah Hartenstein, whose Oklahoma City Thunder dismantled the Knicks by a 126-101 final on Friday night at Madison Square Garden. The Western Conference-leading Thunder earned a two-game sweep of the Knicks after previously prevailing in a 117-107 home win last weekend.

But with Hartenstein, the Knicks were limited to offering a max of four years, $72.5 million. The Thunder gave up three years, $87 million. The reason for New York’s restrictions was it originally signed Hartenstein to a two-year deal, so operated with only his partial Bird Rights. Oklahoma City signed him using straight cap space.

Twenty-one games into his tenure with Oklahoma City, Isaiah has adapted. Still, playing at Madison Square Garden for the first time since Hartenstein signed a three-year deal, $87 million contract with the Thunder, the venue Isaiah called home for two seasons, is unique.

Friday night marked Isaiah Hartenstein’s first time back at The Garden since leaving the Knicks this offseason, and the hometown crowd was sure to give him a warm welcome.

I-Hart still hearts the New York Knicks. Chasing a big contract with the Oklahoma City Thunder may sullied his reputation among some Manhattanites, but Isaiah H