CLEVELAND — Josh Hart’s troublesome knee kept him out of Friday’s embarrassment. 

The Knicks’ Swiss Army knife was ruled out prior to tip-off at Rocket Arena with what the team described as patellofemoral pain syndrome in his right knee, also known as runner’s knee. 

It was Hart’s second straight DNP coming out of the All-Star break, meaning he hasn’t played in nine days.

The forward didn’t travel with the Knicks to Cleveland but could join the club in Boston for Sunday’s showdown with the Celtics. 

Despite the optics of the long layoff, head coach Tom Thibodeau didn’t seem worried. 

“It’s soreness. I think it’s part of our league,” the coach said. “Players have soreness and how do you deal with it and what’s the best course of action to move forward. So you trust the player. You trust medical. And medical weighs heavily on these decisions.” 

Hart has been navigating knee soreness through much of this season but hadn’t been forced to sit games until Thursday’s against the Bulls, an overtime victory that included Miles McBride’s first start of the season. 

A day later, however, the Knicks clearly missed their starting small forward and were detonated by Cleveland’s high-octane offense in a 142-105 loss.

Precious Achiuwa started in Hart’s spot and contributed just seven points on 3-of-10 shooting in 27 minutes. 

“I mean, obviously, he’s — no pun intended — he’s the heart of our team, really,” Jalen Brunson said. “We can’t just say, ‘Oh we don’t have him tonight. Let’s chalk it up as an L.’ That’s not how stuff should go.” 

Hart has been durable since joining the Knicks two years ago, missing only one game last season while finishing 11th in the NBA in total minutes.

The prognosis for runner’s knee, as NYU Langone physical therapist Charles Homoky told The Post’s Mark W. Sanchez, is encouraging as it’s a common ailment that “I don’t think is going to derail a season.” 

While with the Lakers in 2019, Hart had a platelet-rich plasma injection in his right knee, then underwent an ultrasonic debridement procedure on his patella tendon that ended his second NBA season. 

According to the LA Times, Hart dealt with tendinitis in his knee for years before undergoing the procedure. 

Asked before this All-Star break if the persistent knee pain was something he’d have to handle in the summer, Hart didn’t want to speculate. 

“I don’t know. We’ll see what it calls for at the end of the season,” Hart said. “But like I said before, I’m a servant to [my teammates] this year. I want to make sure I put these guys in the best situation. It’s not just for them. It’s also for [Thibodeau]. I want to make sure that I’m available to him. I want to make sure when I’m out there, I’m playing at a high level and playing the game the way I know how to play. If I’m out there, I’m healthy enough. And I’m good.”