Wallaby coach Ewen McKenzie will be sweating over the availability of Waratahs hooker Tatafu Polota-Nau.
The burly, all-action No.2 is the major casualty of the Tahs' historic Super Rugby crown.
Polota-Nau limped off just after half-time in the Waratahs' tense 33-32 win over the Crusaders in the Super Rugby Final in Sydney at the weekend.
Tahs coach Michael Cheika suspected the hooker had a medial ligament tear, which could rule him out of the Bledisloe Cup/Rugby Championship opener in a fortnight.
He will have scans on Monday and, although he was putting on a brave front and saying he remains hopeful of being fit for the start of the Southern Hemisphere championship, Polota-Nau looks little chance of tackling the All Blacks in Sydney on August 16.
With Stephen Moore ruled out for the year with a knee injury, after being hurt two minutes into his first match as Wallabies captain, Australia will lose a total of 141 Tests of experience if Polota-Nau is also scratched.
Such a scenario would likely thrust two-Test reserve Nathan Charles into the Bledisloe Cup cauldron.
The Western Force No.2 and Queensland James Hanson are the back-up hookers in coach McKenzie's Rugby Championship squad.