The troubled Manly fullback Brett Stewart will undergo knee surgery which will see him out of the National Rugby League for eight to 12 weeks.
Stewart suffered the injury in the second half of Manly's win over South Sydney on Saturday.
Early indications after the game were that the injury wasn't serious but subsequent tests have shown it's similar to a knee injury he suffered a couple of years ago and required surgery.
Stewart's sored five tries in his two games this season after he was forced to sit on the sidelines for the first four rounds due to an NRL imposed suspension following his drunken antics at the club's season launch.
He also faces a sexual assault charge after an incident at the launch.