Sharpe handed Australia captaincy
Australia came from behind in Perth at the weekend to beat the Springboks 26-19 but it came at a cost with skipper Will Genia badly injuring his knee, which will keep him out for a prolonged period.
With first-choice captain James Horwill also sidelined, along with his successor David Pocock, Sharpe takes control for the showdown with the Pumas on the Gold Coast, the first Test to be played at the popular tourist destination.
"To have the privilege of leading Australia in the first ever Test to be played on the Gold Coast is an experience I will always treasure," said veteran Sharpe, 34, who has led the Wallabies twice before.
"But the memory is down the track. For now, it's important we keep our focus as a team, build on what we achieved last weekend in Perth, and add to that momentum.
"No one else in the squad has played Argentina before but I have and they will be tough, incredibly passionate and uncompromising.
"You only have to look at what they have achieved to date in their tournament matches to see what a threat they will be."
While winless in the championship to date, the Pumas have made both of their opponents uncomfortable, making most of the running in a 16-16 draw with South Africa at Mendoza last month.
They then gave the All Blacks a scare for much of last weekend's Test in Wellington, which was eventually lost 21-5.
Sharpe goes into the match with a new second row partner after a hamstring injury ruled out Perth man-of-the-match Sitaleki Timani, with Kane Douglas called on to take his maiden Test bow, the only change to the pack.
"He's a big man so he will help anchor the scrum on the tight head side in a similar way to how Sita has," said Wallabies coach Robbie Deans of Douglas.
Halfback Nick Phipps will step up for his fifth Test appearance to replace Genia.
A further change sees Berrick Barnes move from inside centre to full-back, to accommodate the return of regular inside centre Pat McCabe.
This means the out-of-form Beale, who started against South Africa, moves to the bench for the second time in three Tests after being dumped following his shocker in the opening game of the tournament against New Zealand in Sydney.
Australia: 15 Berrick Barnes, 14 Dom Shipperley, 13 Adam Ashley-Cooper, 12 Pat McCabe, 11 Digby Ioane, 10 Quade Cooper, 9 Nick Phipps, 8 Radike Samo, 7 Michael Hooper, 6 Dave Dennis, 5 Nathan Sharpe (c), 4 Kane Douglas, 3 Ben Alexander, 2 Tatafu Polota Nau, 1 Benn Robinson.
Replacements: 16 Stephen Moore/Saia Fainga'a, 17 James Slipper, 18 Scott Higginbotham, 19 Liam Gill, 20 Brett Sheehan, 21 Anthony Fainga'a, 22 Kurtley Beale.
Date: Saturday, 15 September
Venue: Skilled Park, Gold Coast
Kick-off: 20:00 (10:00 GMT)
Referee: Wayne Barnes (England)
Assistant referees: Nigel Owens (Wales), Glen Jackson (New Zealand)
TMO: Matt Goddard (Australia)