Reds prop Ben Daley and flyhalf Ben Lucas face lengthy rehabilitation periods after both suffered injuries in their team's 3-34 loss to the Waratahs at the weekend.
Daley dislocated his shoulder in a scrum collapse in the late stages of the game, the Reds' final league match of the season.
Scans revealed damage to his rotator cuff.
He will have exploratory surgery next week to determine the full extent of the damage.
Lucas suffered an articular defect in his right knee joint during the opening stages of the match and had surgery on Tuesday.
He will be out of action for eight weeks.
The pair join a lengthy list of players undergoing rehabilitation - including Quade Cooper (shoulder/hip), Blake Enever (bicep), Anthony Fainga'a (calf), Chris Feauai-Sautia (shoulder), Nick Frisby (jaw), Will Genia (ankle), Eddie Quirk (knee), Dom Shipperley (ankle) and Aidan Toua (pectoral/hamstring).