Australia reportedly suffered a late blow Saturday when a hamstring injury forced prop Taniela Tupou out of the opening Bledisloe Cup Test against New Zealand in Sydney.
The Wallabies had been relying on the young tighthead to make an impact off the bench as they seek a win to kick-start their quest to end New Zealand's 15 years of Bledisloe domination.
But Sydney's Daily Telegraph said the 22-year-old, dubbed "the Tongan Thor", tweaked his hamstring at training on Friday and would not participate in the Saturday evening match.
It said Tupou, who has earned four caps from the bench and performed strongly in the June series against Ireland, may recover in time for the second Test in Auckland next week.
Uncapped Melbourne Rebels prop Jermaine Ainsley will replace him for the fixture, which also doubles as the Rugby Championship opener, it added.