Utah Jazz forward Lauri Markkanen goes to the hoop between...

Utah Jazz forward Lauri Markkanen goes to the hoop between Knicks center Karl-Anthony Towns, left, and guard Josh Hart during the first half of an NBA game Saturday in Salt Lake City. Credit: AP/Spenser Heaps

DENVER — As Josh Hart sat at his locker after the Knicks’ loss to the Jazz, there were none of the usual jokes or smiles, and he didn’t want to talk about his team’s offensive struggles in Saturday’s game. He had one topic that he wanted to get to, and he did it directly and quickly.

For all the talk about what the Knicks can be, the offensive potential and the time needed to acclimate and adapt to the new roster, Hart sees a problem. And he doesn’t agree with any of the excuses.

New faces? Miscommunication? No, it’s simpler than that.

“Yeah, we’ve been struggling on the defensive side for the whole season,” Hart said. “When you’re not making shots and you’re not playing well defensively, that’s a recipe for disaster. We’ve got to figure it out on the defensive end. We’ve got enough talent on the offensive side where even if certain guys aren’t going that day to play well and to win games. But we’ve got to figure it out defensively.

“We’re just not playing well enough. We’re not being physical enough. We’re not giving enough ball pressure, myself included. We’ve got to figure it out. We can’t just be an offensive team, and that’s what we’ve been for the first 15 games. And when you have games like this where you’re not shooting well and not figuring it out offensively, it looks bad.”

And it did look bad as the Jazz, who entered the game with a 3-12 record, beat the Knicks, 121-106. They took advantage of wide-open three-point shots, shooting 19-for-34 from outside the arc, and they outmuscled the Knicks in the paint with their imposing front line of Walker Kessler, Lauri Markkanen and John Collins, building a 52-40 rebounding advantage.

As the Knicks’ failures mounted on the defensive end, there were expressions of confusion and exasperation and slumped shoulders.

“We have to be more consistent, but for the most part, we’ve got to make sure we have each other’s back,” Jalen Brunson said. “There’s going to be times it’s messed up or an assignment’s missed, or something happens on the defensive side of the ball, but we can’t point fingers. We’ve got to cover for each other. We don’t really point fingers, but we have to cover for each other.”

The task gets tougher Monday night as the Knicks (9-7) take on the Denver Nuggets (9-6), who boast the eighth-ranked offense in the NBA. The Knicks are second in offensive rating but 21st in defensive rating. They rank 24th in effective field-goal percentage defensively and 10th in points in the paint surrendered.

That last one doesn’t bode well as they prepare to face Nikola Jokic, who is putting up MVP numbers again (30.3 points, 13.9 rebounds and 11.3 assists per game). Also, the absence of Mitchell Robinson and Isaiah Hartenstein has been hard to miss.

With Karl-Anthony Towns at center, the Knicks have upgraded offensively in the middle, but there also is a clear drop-off defensively from Robinson, one of the top rim protectors in the game. While Robinson is rehabilitating from ankle surgery, with the team targeting a December or January return, Towns has managed to hold his own on most nights. But the pairing of Mikal Bridges with OG Anunoby has not provided the perimeter shutdown that might have been expected.

Coach Tom Thibodeau, when asked if defenses generally are ahead of offenses at this point early in the season, said: “It depends on what teams you’re talking about. I think it’s really an individual thing. I think you don’t really know who your team is, probably 15 to 20 games in, and again, that’s probably a bigger indication.

“But then there’s a lot of variables to it, whether it’s new guys that you have, whether it’s key injuries that you have. So you probably don’t have a true picture yet of who everyone is and you get that over time.”

Notes & quotes: Towns was added to the injury list, listed as questionable with a left calf contusion.