Australia lock Rob Simmons has been ruled out of Saturday's Test against England at Twickenham and could miss the rest of the tour.
The Queensland Reds forward re-aggravated an old knee injury in a Wallabies' training session on Tuesday.
Simmons now faces a minimum two weeks out, as he receives continued treatment on an injury that first occurred during the 33-41 loss to New Zealand two weeks ago.
The blow means that Waratahs lock Sitaleki Timani is now set to pack down alongside Australia skipper James Horwill in a physical second row pairing.
As Australia's lineout caller, Simmons' absence means Horwill will now split the decision making with Ben Mowen.
Kane Douglas is the other remaining second row option on tour.