"I'm a Shark," the center said Thursday. "There's one team, and it's here."
Thornton, who will turn 40 on July 2, just completed a one-year contract and could become an unrestricted free agent on July 1. He has played with the Sharks since they acquired him in a trade with the Boston Bruins, who selected him with the No. 1 pick in the 1997 NHL Draft, on Nov. 30, 2005, and has 1,024 points (244 goals, 780 assists) in 1,034 games with San Jose. He has played in 1,566 regular-season games, the second most in NHL history for a player who has never won the Stanley Cup behind Patrick Marleau (1,657).
This past season, Thornton had 51 points (16 goals, 35 assists) in 73 regular-season games and 10 points (four goals, six assists) in 19 Stanley Cup Playoff games.
"He can have all the time he needs to make whatever decision's right for him, but we love him," Sharks general manager Doug Wilson said. "I've been in this business a long time, I've never met anyone like him and we cherish the days we have him. Whatever decision he makes, we're there for him."
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Sharks coach Peter DeBoer said, "[Thornton's] still got game. For me, I'd love to have him back."
Thornton said he sustained a pulled groin on the first shift of Game 1 of the Western Conference Final against the St. Louis Blues but that it wasn't a major problem throughout the series. As a result, he won't need rehab this summer, as he did last offseason after having surgery to repair a torn MCL in his right knee on Jan. 25, 2018.
"It weighs on you man, it does," Thornton said. "Some guys are going to have to go through it this summer, and it's a grind. It's mentally tough to do that every single day and not sure what the outcome is going to be. For me personally, I don't have that issue."
While Thornton decides whether to play another season, forward Joe Pavelski, who can also become an unrestricted free agent July 1, said he's confident he'll play for the Sharks in 2019-20.
"I've got a pretty strong belief system that I'll be back here, it's just things that have to work themselves out along the way," Pavelski said. "It's nothing I'm too worried about. We love it here, we really do. Love playing here. I'm sure things will move along, and we'll have talks and see where we're all at."