Setoguchi was tied for fourth on the team with 20 goals last season. He had 36 points in 70 games while playing mostly on the second line.
He added five goals and four assists in 15 postseason games. He scored the overtime game-winner in Game 2 of the first-round series against Colorado.
General manager Doug Wilson says Setoguchi is an important part of the team and that the Sharks have "very high expectations for him."
Setoguchi was the eighth overall pick in the 2005 draft. He has 62 goals and 56 assists in 195 career games.