Samu Kerevi has been ruled out of the Spring Tour squad, set for ankle surgery.
Kerevi went for scans on Monday, after injuring his ankle in the 37-10 Bledisloe loss last Saturday, with some outside hope of recovery.
It wasn't good news for the 23-year-old, though, with the in-form centre posting on Instagram on Monday afternoon that it was 'time for surgery'
Kerevi has been a revelation for the Wallabies this season, especially in the Rugby Championship, overtaking regular outside centre Tevita Kuridrani in the starting 13 spot.
His injury opens the door for Israel Folau to move into the midfield on a permanent basis, after the fullback moved into the 13 spot when Kerevi was replaced on Saturday night.
Wallabies coach Michael Cheika said on arrival in Sydney on Sunday that he was open-minded about playing Folau in the centres, pending Kerevi's availability.
With Henry Speight and Sefa Naivalu in the Wallabies mix, the flexibility to move the outside backs around has increased, after a winger injury crisis earlier in the year.
Cheika could opt to return to Kuridrani at outside centre or shift Speight or Naivalu into that position, having both featured there at Super Rugby level.
Australia's centre combination is one of its most intriguing, especially after Bernard Foley's star turn at flyhalf in the third Bledisloe Test, after spending five Tests at 12.
Inside centre has been problematic for the Wallabies, with their three first-choice 12s (Matt Giteau, Matt Toomua, Rob Horne) injured in the opening Bledisloe in August.
While Kerevi will not be named in the Wallabies' Spring Tour squad, Melbourne Storm flyer Marika Koroibete is expected to be included in the group to travel to Europe.
Australia's squad will convene on Thursday in Sydney before departing for the Grand Slam attempt on Friday.