James Horwill, Australia's captain, will not be suiting up for the Wallabies on Saturday after sustaining a hamstring injury.

Horwill got the injury at training on Wednesday. To date, three Wallabies second-row players are down with injuries, which include Hugh McMeniman and Peter Kimlin

He will remain on the sidelines for, at least, two weeks and will likely miss Australia's fixture against Argentina on Sept 14.

The Wallabies has yet to win a game in the championship and this injury may hinder them from getting back on track.

Meanwhile, Kane Douglas has been given the nod to start in lieu of Horwill and Western Force backrower Ben McMcalman will fill-in the void on the bench.

Wallabies coach Ewen McKenzie is tremendously upset because of the injury, but his primary consideration is the player's safety and recovery.

"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." McKenzie told the Sydney Morning Herald (SMH).

Will Genia still be wearing the captain's armband on Saturday, with McKenzie showing his faith in the scrumn-half.

"Will is a proven leader and has had plenty of success as captain for the Queensland Reds and also for Australia," said Mckenzie.

"He is a player that thrives with the added responsibility and he has always stepped up when given the opportunity to lead. I'm sure this will bring the best out of him."