SAN JOSE, Calif. -- Joe Thornton is coming back for another season at age 40, signing a one-year, $2 million contract with the San Jose Sharks on Friday after briefly contemplating retirement at the end of last season.

Thornton decided in the offseason that he wasn't ready to hang it up after 21 seasons in the NHL, saying he'd only play in San Jose. The Sharks were eager to bring Thornton back, but it took until a week before training camp for the finalized contract.

"Words cannot equate the impact that Joe has had on this franchise since his arrival in San Jose in 2005," general manager Doug Wilson said. "Joe is a generational player who seemingly blazes past an existing Hall of Famer with each game he plays. His leadership and dedication to the organization and his teammates is inspiring. He has the rare ability to make the players around him better and we're excited to see him healthy and back wearing the Sharks crest."

Thornton arrived in San Jose in a franchise-altering trade from Boston on Nov. 30, 2005, turning the Sharks into a perennial Cup contender that never quite wins it all.

He quickly became the face of the franchise, winning the Hart Trophy as MVP in his first season, leading the team to back-to-back conference finals appearances in 2010-11 and a run to the Stanley Cup Final three years ago before a loss to Pittsburgh.

The Sharks hoped to give Thornton a championship last season when teammates and coaches openly talked about wanting to "Win for Joe." But San Jose lost in six games in the conference final to eventual champion St. Louis.

Thornton hurt his groin in the first game of that series and his play suffered for it, despite his two goals and one assist in a Game 3 win. The Sharks then lost the final three games to end the season.

Despite that late injury, Thornton was mostly healthy after undergoing major reconstructive surgery on both knees the previous two years. He played the final 71 games of the regular season and didn't need rehab this summer, which contributed to his decision to return.

Thornton's role diminished last year as he played mostly as a third-line center and often wasn't part of the top power-play unit. But his line with Kevin Labanc and Marcus Sorensen was San Jose's most effective down the stretch and he finished the season with 16 goals and 35 assists.

Thornton had 10 goals and 23 assists in his final 39 games, ranking third on the team in points during that span.

He has always been a leader in the dressing room for the Sharks and his role could be more important this season after captain Joe Pavelski left for Dallas in free agency.

Thornton has 413 goals and 1,065 assists in 1,566 career games with Boston and San Jose. He ranks 14th all time in points and needs just 22 to reach 1,500 for his career. He's eighth in assists and needs 15 to pass Adam Oates. Thornton will move into the top 10 in games played in a career with 49 this year.