The Knicks’ rhetoric about top players wanting to be here because of a new culture, vibe and an engaging head coach in David Fizdale gets put to the test starting Sunday evening at 6 p.m.

Kevin Durant, Kawhi Leonard and Kyrie Irving officially become free agents, and the Knicks have room for two max slots.

Irving already looks like a loss, expected to sign with the Nets without so much as meeting with the Knicks. The landing of Durant is no longer considered the giant bonanza it once was. It’s as much risk as reward after his Achilles tear puts him out next season and he will be 32 when he suits up again. The dream scenario of Durant coming along with another All-Star will have to be Leonard as Irving and Kemba Walker (Boston) are almost certainly off the board.

According to a source, Walker’s family, including his mother, was uninterested in moving back to New York.

The Knicks have appeared to be long shots for Leonard, though ESPN reported Saturday that Durant and Leonard could be open to a union with the Knicks as one of the possible destinations.

If Durant signs, though, it likely will be sans Irving, who is on the verge of signing with the Nets when free agency opens.

Durant will talk via video conference call or meet with reps from the four clubs long in pursuit — the Knicks, Nets, Clippers and Warriors.

Durant refused to meet with the Knicks in 2016, so brass considers its inclusion as a positive development. The Knicks also plan to meet with Leonard in Los Angeles next week.

Golden State still looms as a threat to keep Durant — with the ability to offer an extra $50 million and an additional fifth year, which now may be more enticing to the rehabbing superstar. The Warriors can offer a five-year, $221 million super-max deal compared to the Knicks/Nets/Clippers max options of four years, $164 million — a difference of $57 million.

Former Durant teammate and confidant Kendrick Perkins has fluctuated between believing the Knicks and Nets were favorites, then issued an interesting tweet Friday.

“Brooklyn, New York and the Clippers better have a strong got damn pitch because if I’m KD it’s hard to turn [down] that Super Max with GS!’’ Perkins posted on Twitter.

Warriors general manager Bob Myers reportedly is headed to New York this weekend hoping to meet personally with Durant.

The Knicks have tried to dial back on needing to land the big fish this summer. They have alternative plans for their $72 million of cap space that includes signing second-to-third-tier free agents to one- and two-year deals.

They have interest in point guard Terry Rozier and power forwards Julius Randle and Bobby Portis, a restricted free agent. They have mild interest in center DeMarcus Cousins on a one-year deal.

Durant is within reach, though, and may decide based on other additions. The Knicks were favorites before his Achilles injury. There are so many connections, starting with his agent Rich Kleiman, a New Yorker and longtime Knicks fan.

The buzz at the scouting combine in Chicago in May said Kleiman was in position to grab an important front-office role and become as powerful a decision-maker as GM Scott Perry.

“We’re gonna sell who we are as people and our ability to connect and relate to players, support them and give them the best form to allow them to be their best selves that will ultimately help us win,” Perry told Yahoo Sports.

The Knicks are coming off a 17-65 disaster and have a new theme if they strike out with Leonard, Durant and Irving. They would continue to develop their stock of young players culled from the past three drafts.

“We’re not paying attention to the noise,” Perry said. “We’re gonna continue to be opportunistic and build this the right way.”

Beyond Kleiman, Durant has ties with Knicks assistant coach Royal Ivey.

“[Durant] wants to live in New York,’’ one NBA source said recently.

Durant has recuperated in New York since his surgery at the Hospital for Special Surgery. Durant is a mentor to Allonzo Trier, who played high school basketball in Oklahoma City, and a close friend with DeAndre Jordan, whom the Knicks would like to bring back.

That the Nets have snuck into the KD race is a stunning turn — with Irving’s influence a reason. Brooklyn still gives Durant the chance to live in the city, but it isn’t a legacy move.

Richard Jefferson, who last season became a part-time Nets broadcaster, told The Post during The Finals the Brooklyn tide is rising.

“It’s not anything over the Knicks,’’ Jefferson told The Post. “I just think they’re now included in the conversation with the Knicks, Lakers, Clippers and everybody from things I’ve been hearing. They were one of those outside of those top three. But people are really taking a hard look and see there’s potential there.”

If the Knicks go with second- and third-tier free agents, the mantra will continue to be “patience.’’ In Rozier, the Knicks see an upgrade at point guard. The Knicks have no power forwards on the roster under contract, and Randle is a young bull who has underachieved but has the athletic talent the Knicks crave from their bigs.

New Orleans did not enforce Randle’s option year, leaving the 24-year-old an unrestricted free agent.

“He is a beast, plays hard, but can only get to so far due to how he sees the game,’’ one NBA scout told The Post. “I’m not sure about his basketball IQ and perimeter shooting. And he’s not the most conscientious defender.”

If the KD-Kyrie or Kawhi-KD pairing turns into Rozier-Randle, it won’t be surprising. The Knicks haven’t had much luck these past 18 years.