Havlat, who has two goals and 13 assists this season, suffered a fluke injury Saturday when his skate clipped the boards as he was coming off the ice during a line change.
"He's going to be out for an extended period of time," San Jose General Manager Doug Wilson said. "We thought it was a complete tear, but it was not and it's been repaired surgically. He will be out an extended period of time, but we expect him to be back."
Havlat is in his 11th NHL season, but his first with the Sharks. He has spent five years with Ottawa, three with Chicago and two with Minnesota.