A week and a half ago, the Knicks bruised the Pacers underneath.

There was no Mitchell Robinson, OG Anunoby or Julius Randle, but Isaiah Hartenstein (19 rebounds) and Jericho Sims (four boards in 12 minutes) helped own the paint.

The Knicks outrebounded Indiana by 16, which translated to earning 10 more shot attempts than the Pacers in a Feb. 1 win at the Garden.

Saturday, just about the same Pacers team bossed around a Knicks team that is very much not the same.

Hartenstein and Sims have joined the walking wounded, meaning the Knicks were without three top centers and their two best forwards.

The Pacers grabbed nine more rebounds than Tom Thibodeau’s group and grabbed a victory going away.

“They killed us on the glass last time we were here,” Pacers star Tyrese Haliburton said. “We did a good job of controlling that.”

Suddenly, the Knicks — among the best at asserting themselves and dominating the inside — can be controlled.

Injuries have threatened to turn their greatest strength — in this case, literal strength, size and rim protection — into a weakness if these setbacks linger.

Jalen Brunson’s return Saturday sure helped, but what hurt most was the lack of the Knicks’ paint presences.

Without Robinson, Hartenstein, Sims, Anunoby and Randle, Thibodeau started Taj Gibson — on his second 10-day contract — and Precious Achiuwa underneath. Gibson was ineffective on an 0-for-4 night while Achiuwa (15 points and six rebounds) was a minus-12.

A team that entered NBA action Sunday as the fourth-best rebounding group in the NBA was outrebounded 41-32. Indiana’s starting frontcourt of Myles Turner and Pascal Siakam combined to go a silly 17-for-22 from the floor for 42 points.

“We have to gang-rebound,” Thibodeau said of a team that at one instance asked 6-foot-7 newcomer Bojan Bogdanovic to play center. “We’re not going to be able to rely on one or two guys. We have to put our bodies on people, and then we’re going to have to go fight for the ball. We’re small.”

There is a chance they will remain small for at least a little while. There has been no further update on Hartenstein, who has been called day-to-day after aggravating his sore left Achilles in Thursday’s loss to the Mavericks.