George Karl says the media may want to put the brakes on the runaway hype for Knicks rookie Kevin Knox.

The legendary coach told The Post he’s seen summer-league studs come back to Earth once fall arrives and the NBA’s regular season starts.

Karl was in Albany on Saturday for the screening of the new documentary on the Albany Patroons — “The Minor League Mecca.” Phil Jackson, Bill Musselman and Karl each coached the Patroons in their heyday, the 1980s and early 1990s.

“The Knox kid definitely had a great summer league, but I don’t put a lot of value on summer performance or summer talk,’’ Karl told The Post before Saturday’s premiere. “It’s false energy. The real energy comes when they start performing. And after 15-20 games, you’ll have a better feel if he can be an impact player that can upgrade our team and win games. There’s a lot of guys who can look good and play, but they can take an average or below-average team and make it a team that can win games. I’m not ready to assign that on Knox.”

Karl, who last coached Sacramento in 2016, does believe rehabbing Kristaps Porzingis is a surefire star.

“But I am a big fan of Porzingis,’’ Karl added. “I think getting him healthy, it gives coach Fiz [David Fizdale] a chance to develop Knox and develop some players this year and do it in a winning way so when Porzingis comes back, everybody can get real excited about the possibility of being a playoff team.’’

Karl, 67, still hasn’t given up on coaching again. After writing a recent memoir in which he pummeled Carmelo Anthony, Karl was figured to be done.

“I would love to be involved in the game,’’ Karl said. “Usually you get fired, there’s one, two years of a calming-down period, you go away, they forgive you and bring you back. I’m cocky enough to say I can help a team get better.”

The Knicks didn’t approach Karl for an interview last spring, but the former coach of the Sonics, Cavaliers, Warriors, Bucks, Nuggets and Kings thinks Fizdale was the smart choice.

“I like him a lot,’’ Karl said. “When a coach is hired, I say to myself: ‘Is he a good fit?’ David will do well. He was tutored under Pat Riley in Miami. He has a strong personality. I think he believes enough in himself he’ll be able to take the criticism that comes from being the coach in New York City.”

Karl doesn’t view Fizdale’s short Memphis stint as a bad one.

“I like his personality from a standpoint he wasn’t totally Miami [in Memphis],’’ Karl said. “He had a little bit of own personality, was developing around the strengths of [Marc] Gasol and [Mike] Conley. Then they got hit with Conley’s injury. First year he had a good year and they were moving in the right direction. I don’t know how it fell apart. But I heard the rumors [about a feud with Gasol]. What happened in Memphis wasn’t a negative. It’s what happens in basketball.”

Indeed, Karl had his share of quarrels with All-Stars. He lambasted Anthony in his memoir, writing he was “addicted to the spotlight.’’ That characteristic is hurting him now. Karl believes Anthony should volunteer to go to the bench in Houston.

“I wish Carmelo would try to be [the league’s] Sixth Man of the Year,’’ Karl said. “I think he’d be a great sixth man, come off the bench against the second unit. He still has a first-class offense. Most of the time coaches like a guy who can come off the bench and can light it up a bit. That’s what I think he can handle, but he has to mentally handle it.”

Karl empathizes with Jackson, his fellow Patroons coaching alum. Jackson was faced with an arduous decision on whether to re-sign Anthony in 2014. The move cost Jackson any chance of a successful Knicks presidency (Jackson didn’t attend Saturday’s screening because of a conflict with his reunion at the University of North Dakota).

“Carmelo was a difficult decision,’’ Karl said. “Carmelo lost a step of his talents. Do you hang onto that or do you change that? That’s a very difficult thing to do and it’s when Phil came in. [Carmelo] had plateaued, hadn’t been able to deliver playoff basketball. Was it the team or was it Carmelo? You had to figure that out. Most basketball men believe in the superstars than changing the team.”

Meanwhile, the defending-champion Warriors took the leap this offseason by signing DeMarcus Cousins, former Karl sparring mate.

“Winning will make DeMarcus understand and learn from the process,’’ Karl said. “I don’t see much negative. Only negative I see in their process is: Are they mentally tired? They looked mentality tired last year.’’