Wallabies back Reece Hodge was Sunday ruled out of their third Bledisloe Cup clash against New Zealand next weekend and the upcoming tour of Europe with a fractured ankle.
The utility back, who has played in all nine of Australia's Tests this season, picked up the injury in the team's final training session on home soil on Friday before the squad left for Japan, where they will face the All Blacks.
A replacement is yet to be decided.
Hodge's Melbourne Rebels teammate Angus Cottrell has also been sidelined with a knee problem in a cruel blow for a player who was set to make his debut.
Rugby Australia said it was touch and go whether Cottrell would be fit for the Wallabies final three Tests of the year against Wales, Italy and England in November, with Pete Samu drafted for the New Zealand match.
Hodge's absence is a blow for coach Michael Cheika, who has limited options to replace him.
Samu Kerevi may have to be rushed back having had limited playing time after missing the entire Rugby Championship with a bicep injury.
"He's got a good block of training under his belt and he is probably a bit underdone but he has a lot of experience as well," Cheika told reporters of Kerevi.
"We will decide once he arrives and we get him on the training paddock whether we think he is in the sort of condition he needs to be to play at least some part this weekend."
Revised Australia squad for New Zealand Test:
Jermaine Ainsley, Allan Alaalatoa, Rory Arnold, Adam Coleman, Jack Dempsey, Folau Fainga'a, Ned Hanigan, Jed Holloway, Michael Hooper (capt), Sekope Kepu, Tolu Latu, Brandon Paenga-Amosa, David Pocock, Izack Rodda, Rob Simmons, Scott Sio, Taniela Tupou
Tom Banks, Kurtley Beale, Israel Folau, Bernard Foley, Will Genia, Jake Gordon, Dane Haylett-Petty, Reece Hodge, Samu Kerevi, Marika Koroibete, Jack Maddocks, Sefa Naivalu, Nick Phipps