Australia flanker David Pocock has been ruled out of Saturday's Cook Cup clash with England.
Pocock had been due for a return to action at Twickenham after recovering from knee ligament damage.
But scans confirmed on Monday night that the openside flanker had suffered a calf strain, ruling him out of the game.
Australia will also be without lock Kane Douglas, who played in Saturday's 33-6 defeat to France but is struggling with a knee injury.
Douglas was urged by his family to play against France despite the news that his mother, Trish, had suffered a stroke on the flight from Australia on Friday.
While still in hospital in London, Mrs Douglas is listed as being in a comfortable condition.