Australia have made six changes to the team that lost 15-6 to Ireland ahead of their clash with the USA on Friday, September 23.
Regular captain James Horwill will be rested with a shoulder complaint, with the armband handed to scrum-half Genia.
Rob Horne will play his first Test in more than a year when he comes in at inside centre, while winger Drew Mitchell starts in place of the injured James O'Connor.
Nathan Sharpe and Rob Simmons join the second row, Wycliff Palu comes in at number eight and prop James Slipper starts his first Test of the year.
"It's our second six-day turnaround in a row so we're looking to freshen things up a bit," said Wallabies coach Robbie Deans.
"We trust all of our players, which is why we are prepared to make the changes that we have for such an important match."
Australia: Kurtley Beale, Adam Ashley-Cooper, Anthony Fainga'a, Rob Horne, Drew Mitchell, Quade Cooper, Will Genia (c), James Slipper, Tatafu Polota-Nau, Ben Alexander, Nathan Sharpe, Rob Simmons, Rocky Elsom, Ben McCalman, Wycliff Palu
Replacements: Stephen Moore, Sekope Kepu, Dan Vickerman, Radike Samo, Luke Burgess, Berrick Barnes, Pat McCabe
