AP

SAN JOSE, Calif. (AP) — Before Joe Thornton heads into an uncertain offseason where he could be a free agent and leave San Jose after nearly 12 years, he had more pressing business.

Thornton underwent surgery on a torn ACL and MCL in his left knee Monday to repair an injury that sidelined him less than two weeks before he returned to play the final four games of a first-round series loss to the Edmonton Oilers.

"I've been in this business a long time," general manager Doug Wilson said. "You see a player play with that type of injury tells you all you need to know about him."

Thornton downplayed the injury before the team announced the severity of what he played through and the surgery, calling it simply "the normal stuff that hockey players deal with" at this time of the season.

But his willingness to play four playoff games on basically one leg at age 37, and record two assists, was just another example of how important he is to San Jose and why the team wants him back this summer before he can become a free agent.

"Basically his knee is floating there," coach Peter DeBoer said. "It was as courageous an effort, him doing what he did, as I've ever seen. And I didn't see a drop off in his game. I know the point production wasn't there. I think there's some answers for that, including power play and fatigue and some things like that. Until his level drops where he has to take a reduced role, that's not even on my radar."

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The futures of Thornton and teammate Patrick Marleau are the biggest questions for San Jose headed into the offseason. The two have been the face of the Sharks for years, with Marleau joining as the second-overall draft pick in 1997 and Thornton coming in a trade from Boston in 2005.

"I want to come back," Thornton said. "I think this is a Stanley Cup-caliber team and I think I'm a little bit older and I realize how good this team is. Of course, I'd like to come back. But we'll have to see. I'm sure we'll be talking."

They have been two of the league's most prolific players during their tenure, with Marleau scoring his 500th career goal this season and Thornton recording his 1,000th assist.

Thornton's production fell a bit this season. His 50 points were his fewest in a non-lockout season since he was a teenager in Boston in 1998-99. Thornton was also a key part of a power play that was ranked 25th in the regular season after years of being at the top of the league.

Marleau scored 27 goals this season and played a stronger overall game as evidenced by his improving plus-minus from negative 22 to four.

Both players will turn 38 before the start of next season, raising questions about how long San Jose will want to commit to them.

"Guys like that aren't growing on trees," defenseman Brent Burns said. "Both those guys, you hear about the age stuff, those guys are both in great shape. Every day they put the work in. They're elite players. Age doesn't matter."

Wilson called both players cornerstones of the franchise on and off the ice and seemed interested in them coming back. Both players also publicly expressed the same desire but the sides must come to terms on length and value.

There have been no talks yet between the parties and it is extremely unlikely any deal would be finalized before the expansion draft in June.

The other key questions for the Sharks headed into the offseason are who they will protect in the expansion draft and will they be able to reach long-term extensions with goalie Martin Jones and shut-down defenseman Marc-Edouard Vlasic.

Both players are eligible for free agency in 2018 but can sign extensions after July 1. Wilson said he would like to get those deals done before training camp.

"Both of them are extremely important to get under contract," Wilson said. "Those are priorities."