Australia have lost Pat McCabe and Digby Ioane for the rest of the British & Irish Lions series due to injuries.
Centre McCabe, was carried off in a neck brace during Saturday's highly-physical 23-21 first Test defeat in Brisbane, while wing Ioane damaged his shoulder late in the same game.
Brumbies star McCabe, 25, only entered the series-opener after debutant Christian Lealiifano suffered a heavy collision with Jonathan Davies in the first minute, but was carried off himself following a second-half challenge from Alex Cuthbert.
Ioane completed the full 80 minutes and the severity of the injury was not apparent until post-match test results, by which time the 27-year-old Queensland Red's participation in the second Test had already been thrown into doubt by the issue of an arrest warrant.
"Ioane suffered internal damage to his right shoulder and will also require further follow up scans with surgery a possibility," an ARU statement read.
"McCabe re-injured his neck in a similar location to an injury first sustained last year. He will be seeing specialists in Sydney in the coming days to ascertain the way forward following further scans."
The news is the latest of a series of blows for Robbie Deans, who is expected to call for further reinforcements ahead of Saturday's rematch at Etihad Stadium, Melbourne.
While Lealiifano has been declared fit and Adam Ashley-Cooper has shrugged off a shoulder problem, versatile three-quarter Berrick Barnes is ruled out by concussion.