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.
Around this time last year, Hartenstein started stringing together the results that would eventually translate to his massive payday with the Thunder.
He started his first game of the 2023-24 campaign on Dec. 20, in the aftermath of Robinson’s injury 12 days earlier, and then held that spot for the rest of the season, even as Robinson returned and then got injured again.
“I kinda felt like I was good enough to start probably most of the time,” Hartenstein said Friday before returning to the Garden for the first time as a member of the Thunder. “I think we had a luxury at the time where we had me and Mitch together, so I think you had two starting centers on the same team.”
But Hartenstein’s return served as a glaring reminder of the Knicks’ pressing dilemma a month before the NBA trade deadline.
They don’t have that luxury anymore.
The blueprint that worked for Hartenstein hasn’t become an applicable script for the next batch of candidates.
Robinson hasn’t played a second this season — and his timeline for a return remains unclear.
The Knicks patched that problem by acquiring Karl-Anthony Towns in the preseason, but they don’t have another Hartenstein waiting as a reserve.
If Towns’ knee keeps flaring up, they don’t have a dependable option to plug in seamlessly should he miss time and should Robinson not return.
Precious Achiuwa remains an undersized option.
Jericho Sims flashed his potential at times before falling out of Tom Thibodeau’s rotation.
This is the cost of a depth issue.
This is the consequence of losing someone such as Hartenstein, even if the Knicks did everything they could to keep him.
And that’s what made his first two games against the Knicks — the Jan. 3 thriller in Oklahoma City and the Friday rematch at the Garden — a brutal blend of what could’ve been, what if and what now for Leon Rose and Co.
Hartenstein, for his part, has thrived with the Thunder, averaging 12.2 points, 9.4 rebounds and 4.2 assists per game entering Friday.
His marquee Knicks moments from last season — such as grabbing the offensive rebound that led to Donte DiVincenzo’s game-winning 3-pointer in Game 2 of their playoff series against the 76ers — turned into performances such as Wednesday, when he finished two assists shy of a triple-double.
His style of basketball “brings in wins,” Josh Hart said Wednesday, “and there’s no shock why when he got healthy, got put into that lineup that they went on a rampant 15-game win streak.
“I mean, you don’t ever want anyone to get hurt, but I mean, [Robinson] got hurt at a time and I just kinda seized the moment,” Hartenstein said of his Knicks chance last season. “… It was right timing, for sure, but I felt like I always could be in that position.”
He expected a mix of boos and cheers during his return to the Garden.
And when that all unfolded during a timeout in the first quarter, as the Knicks greeted Hartenstein with a short video, their search for his replacement continued. Achiuwa has collected 5.6 points and 5.9 rebounds per game, but at only 6-foot-8, the Knicks will always face a height disadvantage when he plays center.
Sims went from receiving compliments from Thibodeau for “elite” rebounding in October and starting in December when Towns missed two games to being out of the rotation altogether.
The Knicks could take this dilemma all the way to the deadline.
They could opt to pursue names such as the Wizards’ Jonas Valanciunas, the Hornets’ Nick Richards, the Raptors’ Kelly Olynyk or others, among other names, as The Post’s Stefan Bondy noted earlier this week.
They could decide to keep rolling with Towns, even amid his lingering knee issue.
At the crux of their issue, they still haven’t found their next Hartenstein.
Their next project for Thibodeau to mold.
Their next plug-and-play solution.
The next piece whose worth could skyrocket to $87 million or any other price the Knicks can’t afford to keep.
And they’re running out of time.
