Waratahs full-back Israel Folau has been ruled out of Saturday's match against the Force in Perth by the Australian Rugby Union, following further medical advice regarding his throat injury.
The decision was made by the Australian Rugby Union's Chief Medical Officer Dr Warren McDonald, and was based on specialist medical advice.
"Advice from our medical specialists is that Israel's throat injury hasn't healed to the point where it's in his best interests to return to play tomorrow night," said Dr McDonald.
"This is a player welfare issue, which has been the focus of all medical staff involved in this difficult decision, and we'll continue to work on the plan for his return as soon as possible."
The ARU's Chief Medical Officer takes all medical advice into consideration - including evidence from team doctors and external specialists - before making a decision about a player's fitness to return to play.
The Waratahs are yet to confirm who will take Folau's place at full-back.