Returning from an Achilles tendon rupture didn’t cost Wesley Matthews money. And it probably isn’t going to cost Kevin Durant any either.

“If Wes Mathews can get a max after an Achilles injury, Durant will have no problem,’’ one NBA general manager told The Post.

In 2015, Matthews signed a maxed-out four-year, $70 million package. He never rose to his previous level, and Mavericks owner Mark Cuban was more than happy to dump his expiring contract on the Knicks last January. The Knicks waived him shortly thereafter and he was picked up by the Pacers.

As first reported by The Post, the Knicks are willing to go all-in on Durant when he becomes a free agent Sunday but will proceed cautiously. Durant’s max with the Knicks would be four years, $164 million.

Most NBA personnel men can’t disagree with the Knicks’ belief about the reward outweighing the heavy risk. Maybe 20 years ago, the decision would cause more consternation.

“I would say, what alternative plan is better?’’ one assistant GM told The Post. “I just think if you can sign one of the top three, four players in the league, you do it. Although it is a rough injury I think in 2019, it’s not as rough as in 1999 with the advances. You still sign him given the opportunity.’’

Durant will miss next season and will be 32 when he’s ready to play. The Knicks realize the 2020-21 season could be a load-management year too, when he could be held to 60 games and on a minutes restriction.

Kawhi Leonard, coming off a quadriceps injury, kept to 60 games this past season and was kept fresh enough to lead the Raptors to the NBA championship after being let loose.

Click Here: fjallraven kanken backpack

“If you have the pen out, I’d get the contract signed before the ink dried,’’ one Western Conference personnel director told The Post. “Coming back from an Achilles is worse than an ACL. But Kevin is not great because of his athleticism. It’s more that’s he’s highly skilled than an athlete. Russell Westbrook, when he loses his athleticism, he’ll be in for a shock.

“But you’d need medical staff to sign off on it. Not just a rubber stamp.”

On Monday, one talent evaluator contended a Durant signing has more chance of failure than success, saying “he wouldn’t do it,” adding, “By the fourth year, I can see people wondering when will he come off the cap.”

An NBA executive pointed out Washington’s dire situation with John Wall, who missed half of this season and may miss next season with his ruptured Achilles tendon after signing a super-max $170 million extension.

“You don’t want to be the Wizards and already have $44 million per year on the cap injured,’’ the executive said. “That would be crazy.’’

Others think it would be crazy to pass on Durant, whose work ethic increases his chances of coming back close to his former greatness.

“If it wasn’t a top-five player from this decade, I’d think different,’’ one Eastern Conference coach said. “Considering the level of player, it’s no-brainer.”

The Western Conference personnel man said the Knicks aren’t in a good bargaining position, after missing the playoffs six straight seasons.

Perhaps if Kevin Knox showed more promise, the Knicks could be less desperate.

“Especially with the Knicks, [you sign him],’’ he said. “It’s not an organization that’s been a destination. It’s a team that’s struggled. They have nice young pieces, but nobody who is going to be an anchor or cornerstone. They need a big fish.”

see also

I wouldnt do it: Iffy Kevin Durant status adds to Knicks spectacle

The Knicks don’t enter free agency on June 30 in…

Bobby Marks, the former Nets assistant GM and current ESPN cap guru, has made his pro-Durant beliefs known. He sees the best-case scenario of another tanked season with Durant rehabbing and going for big things in 2020-21 with more cap space.

Durant’s teammate, Draymond Green, is a free agent in 2020, and sources contend they are actually friends despite their in-season blowup.

“I’m on record — Durant to the Knicks is a no-brainer even with the Achilles,’’ Marks told The Post. “Three out of four years for a top-three player makes too much sense. Plus you will have max room [in 2020] and likely a top-five pick next year to add.”

Of course, with the Knicks, nothing seems to go according to form — as evidenced by their failure to win a title since 1973 and just four playoff berths since 2001.

“It’s the Knicks. It’s Antonio McDyess and Amar’e Stoudemire all over again,’’ one NBA scout said of two past acquisitions who became injury busts.