CHICAGO — The Knicks better hope it was just tired legs on Saturday night.

Otherwise, getting throttled by the Bulls with the defense disappearing is a sign of problems even larger than their lack of depth.

On the second night of a back-to-back after a taxing loss to the Thunder, the Knicks ran out of steam in the third quarter of a 139-129 disheartening loss to the Bulls.

Karl-Anthony Towns, who scored 44 points and grabbed 16 rebounds, goes up for a layup during the Knicks’ loss. NBAE via Getty Images

It translated to their first losing streak since early November and ended with Karl-Anthony Towns limping off the court but probably avoiding any serious injury after getting hit on the leg during his and-1 dunk.

“We didn’t play a lick of defense,” Jalen Brunson said. “Offense wasn’t the problem. Our defense as a group just wasn’t there.”

The Bulls (16-19) dropped 41 points in the third quarter and 76 in the second half.

The Knicks (24-12) scored enough behind Towns’ 44-point explosion and Brunson dropping 26 of his 33 in the opening half.

But the defense disappeared with Chicago shooting 54 percent, getting 33 points apiece from Zach LaVine and Coby White.

Zach LaVine, who scored 33 points shoots a jumper during the Knicks’ 139-126 loss to the Bulls on Jan. 4, 2025. NBAE via Getty Images

Brunson, OG Anunoby and Mikal Bridges — who all played at least 40 minutes the night prior in OKC — were benched for most of the fourth quarter when the Knicks launched a comeback that failed after those starters returned.

“Back-to-backs are part of the league,” said Tom Thibodeau, who acknowledged tired legs were likely a factor Saturday. “Couple that with [the Bulls] were off for three days. I knew they were going to be high energy. And I thought offensively we scored plenty. Defensively, we have to do better.

“If they score and you jog back or complain to an official, they’re racing it up. And so that’s where we can be better. I knew this would be as much a mental challenge as a physical one.”

Tom Thibodeau hugs Derrick Rose during the Knicks’ loss. Rose, who was honored by the Bulls, played for Thibodeau with the Bulls and later the Knicks. NBAE via Getty Images

The third quarter was the story.

It was a sloppy mess for the Knicks with seven missed treys on seven attempts.

Their nine-point halftime advantage turned into a 15-point deficit heading into the fourth quarter, and Thibodeau’s squad never recovered.

Jalen Brunson is fouled by Josh Giddey during the Knicks’ loss to the Bulls. AP

Just like Friday in OKC, Thibodeau maintained an eight-man rotation and his bench was outscored by Chicago’s, 31-17.

He doesn’t trust his bench, which was predictable.

The Knicks exhausted so many resources building an elite starting lineup, it was left cobbling together a bench from second-round rookies, Precious Achiuwa’s Bird Rights and zero cap space.

Coby White, who scored 33 points, drives to the basket during
the Knicks’ loss to the Bulls. NBAE via Getty Images

The upside is the starters are producing even better than expected, hastening their cohesion by logging so much time together on the court.

But the downside is the Knicks aren’t built to withstand injuries — like the strained hamstring to Miles McBride — or tired legs from the starters.

On Saturday, much of that five-man lineup looked gassed and was dominated, with the Knicks being outscored by 21 points in Bridges’ 33 minutes.

Derrick Rose talks to the crowd during halftime of the Knicks-Bulls game. NBAE via Getty Images

Josh Hart, who managed just two points in 40 minutes and missed all five of his field-goal attempts, eschewed the tired excuse.

“We were scoring, but I don’t think there was a real flow to the game,” he said. “Tired legs? We’re not even halfway through the season yet so legs can’t be too tired. We didn’t execute. We didn’t play as good as we should have. We didn’t deserve to win this one.”

For the Bulls, it was a celebratory evening for a couple of reasons.

The other was Derrick Rose Night, which brought the NBA’s youngest MVP back to the United Center for a series of video tributes, guest appearances from former teammates like Luol Deng and an extended halftime show.

The Knicks came out of that break two steps slow.

“We could make every excuse under the sun if we wanted to,” Towns said. “At the end of the day, OKC found a way to beat us. Chicago found a way to beat us. Simple as that. We could make excuses about every little thing. But at the end of the day, they found a way to beat us.”