The Knicks organization is “shocked and disappointed’’ it didn’t get its man Donovan Mitchell and that he’s heading to an Eastern Conference rival, the Cavaliers. 

Cleveland will form a backcourt of Darius Garland and Mitchell and, on paper, clearly are superior to the Knicks. 

“Jazz Stinger,’’ indeed. 

There are indications the Knicks never got a chance to make their very best offer before Jazz president Danny Ainge fell in love with the Cavaliers’ package, which included three unprotected first-round picks — something Knicks president Leon Rose had refrained from including in his offers. 

It was no coincidence the Knicks announced the official signing of RJ Barrett to a contract extension moments before ESPN broke the story Mitchell was Cleveland-bound. 

In fact, according to an NBA source, the Knicks’ would have preferred not to sign Barrett to a hefty contract extension at this moment. They wanted to at least wait until the mid-October deadline to see him at training camp — or even until July 1, when he would have hit restricted free agency. 

Barrett was drafted before Rose’s and senior executive William Wesley’s time with the team. Knicks general manager Scott Perry made the Barrett pick in 2019, and even then it wasn’t unanimous. 

“They didn’t want to pay RJ now, they like RJ, but he’s not one of their guys,’’ the NBA source said. “The preference was to trade him in a Donovan deal. … [I]f they got Donovan without Barrett in the deal, they weren’t going to pay RJ now.’’ 

The source said once the Knicks caught wind the Cavaliers were in the lead for Mitchell, they made a move toward agreeing to terms with Barrett. 

“They had to do something,’’ the source said. 

The Knicks still thought they could make a deal without Barrett and offer better draft capital, but by then Ainge’s talks with the Cavaliers had sped up and the Knicks couldn’t get back in control of their own destiny. 

The Knicks’ initial refusal to give up three unprotected first-round picks if Barrett was in the deal proved to be a decision Rose will have to live with. 

It’s unclear if the Knicks offered three unprotected first-round picks in a deal that did not include Barrett. ESPN reported the Knicks’ best offer was two unprotected picks and a third with a top-4 protection. 

Knicks chief strategist Brock Aller formerly worked as the Cavaliers’ capologist and is friends with Cleveland owner Dan Gilbert, so presumably the Knicks knew what offers they were up against. If they didn’t, it’s a Knicks fail. 

Ainge wound up accepting the Cavaliers’ three first-rounders, two pick swaps, Collin Sexton, who is coming off knee surgery, disappointing lottery pick Lauri Markkanen and 2022 first-round pick Ochai Agbaji. 

There is a sentiment around the league that all things being equal, Ainge preferred to keep Mitchell away from the Knicks. Mitchell wanted to go to his hometown Knicks and the chances of him turning into a bigger star loomed large in the media capital (though Mitchell sounded excited on social media to join Garland in the Cavaliers’ backcourt). 

“I think Danny was thinking if he was giving [Mitchell] to New York, he wanted to rob them,’’ another NBA executive said. “He knew how much they wanted him.’’ 

Whatever the reasons why the Mitchell trade fell through for the Knicks, some league officials feel they missed out on a golden opportunity in getting a homegrown star who wanted to play in New York. Those chances don’t come along often. 

“They didn’t get him, period,’’ one NBA personnel man said. 

In college, Barrett was called “Maple Mamba” — a nickname the Canadian native no longer embraces after Kobe Bryant’s death. His moniker now, after his four-year, $120 million contract extension that includes incentives, is “The Franchise.’’ 

Rose’s statement called Barrett “a core of our team’s foundation.’’ 

“We believe he will continue to improve because of his passion for the game and dedication to his craft,’’ Rose said. 

One team executive, however, compared Barrett to Tobias Harris as “the third-best player on a contending team.” 

“RJ Barrett is a skilled player who lacks elite athleticism and physical dimension to be a franchise player but his virtues are competitiveness, scoring skills and toughness,’’ the executive said. “But he needs a better off-hand, ability to work without the ball and consistency.’’ 

The Knicks still have 11 first-round picks across the next seven years, although that number could decline once the NBA finishes its investigation of alleged tampering with Jalen Brunson.