So I guess we finally understand why Joe Thornton missed two games — two whole games! — of the Sharks’ six-game playoff loss to Edmonton.

It seems that the inside of Thornton’s left knee was doing an imitation of spaghetti. With his ligaments being the spaghetti. Thornton had a torn ACL and a torn MCL, sustained in an April 2 regular-season game at Vancouver. He returned to action on April 16 in Game 3 against the Oilers and contributed two points over the final four games while averaging almost 20 minutes of playing time.

“Just the normal stuff hockey players have to deal with, ” Thornton said of his injury, though it was far more than that.

“Basically, his knee was floating around,” said Sharks coach Pete DeBoer, who added that he had seen few players, if any, be as courageous as Thornton was under the circumstances.

Can’t mince words here. Hockey players have long been known as the toughest athletes on the planet. It’s the culture. But sometimes, you wonder if the culture goes too far over the line. Thornton’s choice was brave and amazing. It was also a pretty stupid choice when it came to his long-term future.

Thornton is 37 years old. He will become an unrestricted free agent on July 1. But after putting his knee on the line for his team, he underwent surgery Monday afternoon to repair the damage.

Which means: Any team that was thinking about signing Thornton to a free-agent deal would surely want to see how his knee recovers from the surgery — but with a six-month recovery and rehab period ahead of him, no one will know for certain about his status until October, which is when the NHL season starts.

Which almost surely means: Thornton is likely to receive no free agent offers this summer — or at least no multiyear offers, which he’s said to prefer.

Which furthermore means: Thornton’s unfortunate injury could benefit the Sharks. They have exclusive rights to Thornton regarding a contract extension until July 1. It’s a safe assumption that the team wants him back. But if general manager Doug Wilson wishes, he could use the situation as leverage for terms that are more favorable to the team. That could include less money or a shorter contract term.

Which calculatedly means: Thornton is not in the best negotiating position, despite being one of the NHL’s all-time top 25 point scorers. His current deal, which is expiring, paid him $6.75 million in each of the past three seasons. The Sharks’ next contract offer was always going to call for Thornton to receive a smaller salary, maybe in the $4 million range for each of the next two or three years. Wilson is now in position to squeeze those numbers even tighter, knowing that no offers from other teams are probably going to be there.

Which callously means: If Wilson actually did decide to use that tactic, he would venture into Snidely Whiplash territory, given the sacrifice Thornton just made for the franchise and his teammates. Fans would be irate. They would see Wilson and the beloved Los Tiburones as cold and cruel negotiators, taking advantage of a man’s willingness to play hurt.

Which realistically means: There is no way that Wilson would invoke the Snidely Whiplash option. It would be horrible public relations for the team. Plus, as a former player himself, Wilson genuinely admired the way Thornton spilled his guts for the team. How could anyone not? It also helps Thornton that he has a personal relationship with Sharks owner Hasso Plattner, who is a big Jumbo fan.

Which theoretically means: The Sharks and Thornton — represented by his agent/brother John — might have come to a handshake agreement about a contract extension before Joe decided to play in Game 3 against Edmonton, putting his knee on the line. It’s hard to believe Thornton would lace it up without such assurance.

Which practically means: The handshake deal can not be formally consummated or announced until after the June 19 expansion draft involving the NHL’s new Las Vegas franchise. Otherwise, Thornton would have to be placed on the Sharks’ protected list, taking the spot of a younger Sharks player who the team might wish to shield from that draft.

“I’ve been in this business a long time,” Wilson told reporters on Monday regarding Thornton. “You see a player play with that type of injury, it tells you all you need to know about about him.”

That remark could have tipped Wilson’s hand. He knows that when your team’s oldest player and team leader goes the extra mile of agony in pursuit of victory, as Thornton did, then his teammates will do the same. Patrick Marleau played in the Edmonton series with a broken left thumb. Tomas Hertl played with a broken foot, Logan Couture with a severely damaged mouth. Joonas Donskoi was battling a hinky shoulder that had been separated twice during the season.

Wilson has many issues to face in the offseason, including what to do with Marleau, another franchise stalwart and upcoming free agent. There are other players due contract extensions that could create salary cap complications. But after Monday’s revelations, it’s pretty clear that the Sharks are going to retain Thornton and give him a decent deal. If they don’t, how would it look?

“I’d like to come back,” Thornton said before heading off to his surgery. “But we’ll have to see.”

Thornton also said that on July 1, he and his family will probably be in Switzerland visiting his wife’s relatives. It would be a surprise if he isn’t signed to a new Sharks contract by then. In a strange way, his spaghetti knee and decision to play injured almost guarantees it.