The “Slim Reaper” nickname might apply off the court, too.

Kevin Durant is trying to become both a coach- and GM-killer.

The Nets superstar wants head coach Steve Nash gone, The Post confirmed, and reportedly has demanded general manager Sean Marks be fired, too.

Durant, who requested a trade in June and has not been moved, had a face-to-face meeting with Nets owner Joe Tsai in London this weekend, The Athletic reported Monday, in which he issued an ultimatum: Trade me or fire them.

According to the report, the Nets have “direct knowledge” concerning why the 12-time All-Star has asked out a year after he signed a four-year, $198 million extension. Also according to the report, Durant “does not have faith” in the direction of the team.

The Nets did not respond to a request for comment. A message sent to Rich Kleiman, Durant’s business partner, went unanswered.

A source close to the Nets organization indicated Durant is not the only Nets star unhappy with the team’s leadership.

“Kyrie Irving hates these guys,” the source said. “He feels that Nash is terrible and Marks is bad.”

“KD came to the same conclusion,” the source added.

The Nets have not found a trade offer that would prompt them to deal the all-time great, and according to the report, Tsai and the Nets have made it known they would take “every last asset from a team that trades for Durant.” In stating the lofty hope for the trade return, perhaps the Nets believe Durant would be less motivated to leave and more likely to report to September’s training camp.

But as the ultimatum becomes publicly known, it is difficult to imagine an avenue toward Durant playing again with the Nets or showing up to preseason action with a team put together by Marks and coached by Nash — unless Tsai chooses the player over the organization’s leaders.

The Nets are seeking a young All-Star and a collection of draft picks for Durant, but finding equal value for a 33-year-old prodigious talent signed through 2025-26 is challenging.

Brooklyn is coming off a chaotic and wildly disappointing season in which the unvaccinated Irving was banished until December and then primarily could only play in road games; James Harden, dealing with a heavier burden without Irving, forced his way out and was flipped for Ben Simmons, who never actually stepped foot on the court; and the Nets eventually were swept out of the first round by the Celtics — who are coached by former Nets assistant Ime Udoka, whom Durant likes.

In the aftermath of the tremendous flop, Marks said the team culture “isn’t what it quite was” and said it was his and Nash’s “job to pick that up.”

Durant, who asked for a trade one day after Irving picked up his own $36.5 million player option, does not want the GM and coach combination to be able to follow through.

Nash had developed a relationship with Durant toward the end of the point guard’s career, when they would work out together in offseasons. Nash then was a player-development coach in the three seasons Durant spent with the Warriors.

But it is possible Nash’s stronger bond is with Marks, his former Suns teammate and longtime friend who gave him the keys to a team with immediate championship expectations in 2020. Through an often bizarre two seasons, Nash’s teams have gone 92-62 in the regular season with just one postseason series victory.

“Joe [Tsai] has tried to make too many decisions himself,” including choosing the coach, the source said.

After the Game 4 loss to Boston, Durant expressed his appreciation for Nash, whom he has consistently publicly supported, and said he was the right coach to lead the Nets into the future.

“Steve’s been dealt a crazy hand the last two years,” said Durant, a two-time NBA champion with the Warriors. “He’s had to deal with so much stuff as a head coach, a first-time coach. Trades, injuries, COVID and just a lot of stuff he had to deal with.

“I’m proud of how he’s focused and his passion for us. We all continue to keep developing over the summer and see what happens.”