Thornton will begin the skating portion of his offseason training next week in Switzerland, where his wife, Tabea Pfendsack, is from.
"There's nobody that loves the game more than him," Wilson said. "Nobody works harder, and I think because of the love of the game, I think he's going to come back excited.
"He's just a unique player. He's one of the great players that have ever played this game. He's a generational-type guy and with his leadership and mentorship to all our guys, we can't wait to see him back in the room in training camp."
Thornton said he feels so good that he has no timetable for how much longer he'll keep playing.
"I've never been hurt in my whole career and the last two years I got two injuries, so you never know what can happen," he said. "As of this moment, I feel great. I don't know what tomorrow brings, but I'd like to play as long as I can. Staying healthy, I think I can."
Odds are he'll do it only in San Jose. For the second straight offseason, Thornton was flexible with his contract demands to help Wilson try to make other moves.
"That's just unheard of, but that's the type of guy Joe is," Wilson said.
Last offseason, it was trying to entice longtime Sharks forward Patrick Marleau to re-sign, but he signed a three-year, $18.75 million contract with the Toronto Maple Leafs.
This offseason, it was trying to give Wilson the room under the NHL salary cap to sign unrestricted free agent center John Tavares, who also chose the Maple Leafs, signing a seven-year, $77 million contract Sunday.
"It would have been nice to get Johnnie, but I think you look at our team still, Doug and [owner] Hasso [Plattner] and [coach] Pete [DeBoer], they've allowed us to compete every year, and I think it's no different again this year," Thornton said. "We're going to compete for a Cup."