Options to consider to replace Isaiah Hartenstein

As NBA free agency enters its second week, the Knicks still have a significant rotation hole to fill — namely a viable big man to replace departed center Isaiah Hartenstein.

The Knicks currently have Mitchell Robinson, who has undergone two ankle surgeries in the past seven months, and the little-used Jericho Sims on the depth chart at center after Hartenstein walked away on a three-year, $87 million contract from the Thunder in free agency.

Team president Leon Rose creatively managed to keep the Knicks under the first apron of the salary cap by including foreign pieces in the blockbuster trade with the Nets for Mikal Bridges.

But several big-name players who fit the profile of the Knicks’ needs to replace Hartenstein — such as Andre Drummond, Mason Plumlee, Goga Bitadze and Mo Bamba — have already signed new contracts elsewhere.

So who is left for the Knicks, who have a $5.17 million mid-level exception to offer taxpayers, to consider?

Here are some remaining possibilities with Summer League set to open in Las Vegas later this week:

Precious Achiuwa

The Bronx product played a valuable role amid various injuries following his midseason arrival from Toronto as part of the OG Anunoby deal, averaging 7.6 points and 7.2 rebounds in 49 games (18 starts) with the Knicks.

The unrestricted free agent, who can be re-signed using his Bird rights, has played both center and power forward depending on others’ availability.

But Tom Thibodeau prefers Achiuwa in 4th place.

He’s slightly shorter than him at 6-foot-8, and that’s a lot to ask if Robinson is sidelined for long periods.

Walker Kessler

The Jazz’s 23-year-old center fits Thibodeau’s profile as a basket protector with 2.4 blocked shots per game last season, second-most in the league behind Spurs rookie sensation Victor Wembanyama.

The 7-footer was also a member of Team USA at the 2023 FIBA ​​World Cup alongside Bridges, Jalen Brunson and Josh Hart.

Kessler has a favorable contract with a $2.97 million salary cap hit for 2024-25 plus a club option, but league executives have expressed skepticism, according to The Post’s Stefan Bondy, that the Knicks have enough assets to make a deal after the Mikal Bridges trade.

Robert Williams

The Knicks are expected to include some salary to bring in the former Celtics big man, who spent an injury-shortened season with the Trail Blazers after the Jrue Holiday trade.

Williams is returning from knee surgery and has two years and nearly $26 million remaining on his contract.

It would be risky for the Knicks to send a rotation player like Donte DiVincenzo to Portland to match his salary.

Daniel Theis

Perhaps the Knicks could substitute one German product for another.

Theis, 32, is strong around the basket and can also serve as a stretch big capable of scoring from 3-point range, converting 37.1 percent of his three-point shots last season with the Clippers.

JaVale McGee

The three-time NBA champion is now 36 after playing 46 games as a backup for the Kings last season.

But the 7-foot-4 McGee has averaged 1.4 blocks per game over 16 NBA seasons and could be viewed as a stopgap reserve and veteran presence, similar to former Knicks forward Taj Gibson.

Nick Richards

The Hornets’ fourth-year center averaged career highs with 9.7 points, 8.0 rebounds and 26.3 minutes per game last season.

Richards, a Jamaican native who played college football at Kentucky, is set to earn $5 million each of the next two years.

Paul Reed

Former Joel Embiid backup was released by the 76ers last week after Philly signed Andre Drummond in free agency.

But the 6-foot-10 Reed is not considered a top-notch defender (0.8 blocks per game in his career).

Prior to the Knicks’ six-game playoff exit to the Sixers, Reed also publicly stated that his team preferred to face the Knicks in the first round because they were an “easier” opponent than the Celtics.