Brisbane, Sep 5 (IANS): Australia national rugby union team 'Wallabies' captain James Horwill has been ruled out of Saturday night's Rugby Championship Test match against South Africa here due to a hamstring injury.

Horwill suffered a hamstring strain during training Tuesday afternoon and has been replaced by Kane Douglas in Australia's second-row, while Will Genia has been named as captain in Horwill's absence, reports Xinhua.

Horwill is set to be sidelined for two weeks after undergoing precautionary scans. He will also miss the Test match against Argentina in Perth next week.

"It's extremely disappointing to lose James but after discussions with medical staff we felt it was important not to risk further injury when he isn't ready," Wallabies coach Ewen McKenzie said in a statement Thursday.

"Scans revealed his injury was on the lower-end in terms of severity and we expect him to be back to full fitness when we embark on our two-game tour of South Africa and Argentina in a few weeks."