The Islanders confirmed Friday night that DiPietro is scheduled to have surgery Tuesday.
Islanders general manager Garth Snow said the best-case scenario for DiPietro's return was the beginning of April, according to a report in Newsday.
The 30-year-old goalie has played eight games this season, going 3-2-3 with a 3.73 goal-against average. He hasn't played since suffering a groin injury Dec. 3 in Dallas.
DiPietro has played only 63 games the last three seasons, missing time because of hip and knee injuries and facial fractures. He signed a 15-year, $67.5 million contract before the 2006-07 season.