Wallabies David Pocock and Kurtley Beale have played their last games of Super Rugby for the season and may be in doubt for Australia's back-to-back tests against the All Blacks next month.
Openside flanker Pocock was left out of the Western Force squad for their last two matches of the season in New Zealand because of a groin injury.
Beale, who has played at fullback and flyhalf this season, sustained a rib injury in the Melbourne Rebels' match against the Queensland Reds last weekend and will be out for up to six weeks.
The 23-year-old, one of Australia's most dangerous backs, missed three of his country's four matches in June, returning for the third test against Wales in Sydney.
His absence for the two tests against world champions New Zealand that kick off Australia's campaign in the inaugural Rugby Championship would be a blow to coach Robbie Deans.
There is already a question mark over another of Australia's best young backs James O'Connor, who will also miss the Rebels' last two matches in South Africa because of a hamstring injury.
''Shattered I can't be in SA with the boys,'' Beale tweeted. ''Got to remain positive and get body right.''
Although there was no word for the Force on how long Pocock would be sidelined, Deans would not be keen on going into the match against the All Blacks in Sydney on August 18 without him.
Pocock's work at the breakdown is key to Australia's ability to slow down opposition ball and he captained the Wallabies in the four June tests in place of James Horwill, who has already been ruled out for the rest of the year by a hamstring injury.
The Zimbabwe-born loose forward might also have played his last match for the Force after seven years in Perth as he is out of contract at the end of the season and a target for the ACT Brumbies.
The Rugby Championship replaces the Tri-Nations with Argentina joining Australia, New Zealand and South Africa for the first time in the southern hemisphere's annual international championship.
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