Mowen becomes the Wallabies sixth captain in two years and will take over the reins in just his seventh Test, making him one of the most inexperienced skippers in Australian history.

Halfback Genia has been axed to the bench with rookie Nic White to take over the No.9 duties.

Wallabies coach Ewen McKenzie revealed the decision to bench Genia was not taken lightly, "The fact that Will has captained his country shows what high regard we hold him in, and while he is naturally disappointed, I also know how competitive he is and I've got no doubts he will train himself to a standstill to bounce back as a better player," McKenzie said.

"We've spoken about what areas we believe he can continue to improve and evolve his game and he was receptive to going back and addressing those things.

"In the end, it wasn't an easy decision because he is undoubtedly a world-class player."

In other changes, prop Ben Alexander returns to the starting XV at tighthead while Quade Cooper retains his place at five-eighth.

White has only played 16 minutes of Test rugby and made his Wallabies debut last month.

Wallabies coach Ewen McKenzie has made changes as the team searches for a win to snap its four-game losing streak.

The Wallabies are already without regular captain James Horwill (hamstring) while leader David Pocock is still recovering from a knee reconstruction.

McKenzie hasn't won a match as Test coach after taking over from Robbie Deans in July.

A defeat at the hands of Argentina would be a massive blow to Australian rugby.

McKenzie remains confident of avoiding any banan skins against the Pumas, "Rugby is a game of chess and we will look forward to the challenge of getting the right balance and our first Rugby Championship win," the coach said.

Mowen only made his Test debut in June against the British and Irish Lions. In his six Tests, he has won just one match.

The ACT Brumbies captain has been outstanding at the Canberra franchise.

He moved to the capital at the start of the 2012 season for a fresh start after years at the NSW Waratahs trying to break into the Test squad.

Mowen feared his international window had closed.

But switching to the Brumbies has reinvigorated his career and he is widely regarded as one of the best leaders in Australian rugby.

At the start of the year Mowen turned down lucrative offers from Japan to stay in Australia and chase his Wallabies dreams.

It has paid off.

He helped guide the Brumbies into the Super Rugby final, made his international debut against the Lions and has established himself as a crucial cog in the Wallabies forward pack.

White will fill the hole left by Genia.

His kicking game will be a massive boost for the Wallabies but Genia's absence leaves a gaping hole in Australia's experience.

White sat on the bench behind Genia last year, but was never given a chance on the field.

When White made the tough choice to have shoulder surgery instead of playing in the Rugby Championship last year, Genia suffered a season-ending knee injury and Nick Phipps was given a chance in the Wallabies No.9 jersey.

But White continued his impressive rise from club rugby this season and has earned the right to test himself against the Pumas.

Wallabies team to play Argentina on Saturday in Perth: 1. James Slipper, 2. Stephen Moore, 3. Ben Alexander, 4. Rob Simmons, 5. Kane Douglas, 6. Scott Fardy, 7. Michael Hooper, 8. Ben Mowen (c), 9. Nic White, 10. Quade Cooper, 11. Nick Cummins, 12. Christian Lealiifano, 13. Adam Ashley-Cooper, 14. James O'Connor, 15. Israel Folau. Reserves: 16. Saia Faingaa, 17. Scott Sio, 18. Sekope Kepu, 19. Sitaleki Timani, 20. Ben McCalman, 21. Will Genia, 22. Matt Toomua, 23. Tevita Kuridrani