David Pocock is out for the rest of the series against England with a fractured eye socket that has rocked the Wallabies chances.
Australia coach Michael Cheika said the game changing backrower would be out for six to eight weeks.
Pocock is believed to have sustained the damage in a cleanout in the final minutes of the 39-28 first Test tumble to England on Saturday night in Brisbane.
"It is a blow no doubt. We are weighing up options to go like for like or a change up" Cheika said.
Bringing an onballer into the mix would give hope to Liam Gill being called up for next Saturday night's second Test in Melbourne on the bench.
With Pocock playing No.8 for the Test side but playing an openside flanker role much of the time, the whole backrow mix will change.
"We have Wycliff Palu, Benny McCalman and Sean McMahon so we have different options for what we want in the backrow," Cheika said.