LOS ANGELES — After his team allowed 144 points in its latest defensive dud, RJ Barrett briefly struggled to find a reason for the Knicks’ high porosity.
He quickly landed on Mitchell Robinson.
“I think we miss Mitch, that’s the first thing,” Barrett said after the Knicks were roasted by the Clippers on Saturday night.
It was always assumed the Knicks would take a step back without Robinson, who underwent ankle surgery last week.
But not to this degree.
In the past six games — including four without Robinson (and really five since he was laboring during the defeat to Boston) — the Knicks are allowing (shield your eyes) 132 points per contest.
During that stretch, opponents are shooting a ridiculous 52.3 percent and scoring 54 points in the paint. Stacked up against the entire season — when the Knicks are allowing just 111.8 points on 48 percent shooting — these are alarming numbers.
There’s a reason Robinson, 25, was an All-Defense candidate before his injury.
“I think right now you can see how much he cleans up for us,” Barrett said. “Just how much his presence — he cleans up the mistakes that we make. Just grabs all the rebounds. That’s a huge part of the defense.”
The Knicks (14-11) have no choice but to figure this out.
Robinson is only expected to be “reevaluated” in about seven to nine weeks, and there’s no guarantee that reevaluation will put him on a course to play by February.
They don’t have enough time to tread water while giving up buckets of points without their center.
Tom Thibodeau has started Jericho Sims, the raw 25-year-old.
But the lineup has struggled with Sims — posting a -17.7 net rating — and Thibodeau doesn’t have much faith in it, anyway.
Sims, limited offensively and struggling to control fouling like Robinson earlier in his career, is still only averaging 18.6 minutes as a starter, leaving Isaiah Hartenstein as the top paint protector.
Thibodeau, known throughout his career as a defensive mastermind, said last week that he’s kept Sims as the starter since the Knicks had been winning (going back to last season, they’re now 11-9 with him as the starter). Plus, it maintains Thibodeau’s preferred rotation with Hartenstein coming off the bench.
But this defense isn’t sustainable.
And it doesn’t make sense if Sims is subbed out after two minutes and two fouls like Saturday night’s defeat to the Clippers.
The next obvious move is to start Hartenstein, and allow the athletic Sims to push the pace with the reserves.
“That’s not my job to make those decisions,” Hartenstein said. “Whatever the team needs I’m ready. I feel like it can work. Just have to make sure when I come in, keep making an impact to get the lead back.”
If Thibodeau doesn’t change the center rotation, another option would be to reinsert Quentin Grimes into the starting lineup.
Grimes is a better perimeter defender than the current starter, Donte DiVincenzo, and the Knicks have also been getting cooked by opponents’ 3-pointers.
But starting Grimes again opens up a different can of worms since the guard basically campaigned to move to the bench, having struggled to find offensive opportunities in a lineup with Barrett, Jalen Brunson and Julius Randle.
“We’ve got to scratch out wins. You look at everything all the time,” Thibodeau said. “Right now no one’s playing great defense. We’ve got to fix that as a group.”
The one clear answer, as Barrett said, is the Knicks miss Mitch.
But when he’s coming back and how they replace him are murkier.
“Obviously he covers for a lot on that end for us and it’s hurting us not having him around,” Randle said.
