Australian second-row Izack Rodda has been ruled out for the rest of the season with a shoulder injury.
The 21-year-old will undergo surgery, meaning he won't feature again this season, starting with Saturday's game against New Zealand in the Bledisloe Cup.
The Wallaby, who made his debut in the 35-29 defeat against the All Blacks in August, had carried the injury through the back end of the Rugby Championship but decided to end his season to be ready for 2018.
Australian coach Michael Cheika appeared to have settled on Adam Coleman and Rodda as his favoured locking duo, after a long period of uncertainty over the Wallaby locking combination.
Rodda's injury will force Cheika to turn to either the hardened Rob Simmons or another rookie, in two-Test Queensland Red Lukhan Tui for Saturday's match. Simmons would be the more experienced option over the versatile Tui who can play also play back-row.
The All Blacks have already retained the Bledisloe Cup with victory in Dunedin in August, leaving Australia, who will be taking on Wales, England and Scotland in November, aiming to prevent the world champions from a clean sweep in the three-match series in Brisbane.
Watch Australia vs New Zealand at 10:00am, Saturday 21st October live on Sky Sports Arena.