PHILADELPHIA -- Philadelphia Flyers forward Justin Williams will have reconstructive knee surgery that is expected to keep him out the rest of the season.

The 21-year-old right wing injured his left knee Saturday in a victory over Tampa Bay. He will have an operation to repair the torn anterior cruciate ligament and will miss four to eight months.

''It's usually a long rehab period,'' said team Peter DeLuca, who will perform surgery Thursday. ''There is an outside possibility that he can return for the playoffs.''

Williams has eight goals and 15 assists this season with the Flyers.

On Sunday, the Flyers recalled forward Mark Greig from the AHL's Philadelphia Phantoms to take Williams' spot. Greig has 13 goals and 27 assists in 124 career NHL games.