Scrum-half Will Genia will captain an Australian side showing six changes from the one that lost to Ireland in Friday’s Pool C World Cup match against the United States.

In the absence of rested lock James Horwill, Genia will captain a side that has been tweaked by coach Robbie Deans to give most squad members a run-out after the first two matches (a 32-8 win over Italy and 15-6 loss to Ireland).

“We’ve got a big job ahead of us. The United States showed against Ireland that they are a totally committed opponent,” said Genia.

“Our own performance against Ireland, which was not up to the high standards we set for ourselves, will only have offered the Americans further encouragement.”

Genia added: “We just need to get out there and get it done, and that’s pretty much the focus of the whole group. We’re obviously disappointed with last week and want to go out there and make things right.

“It was one poor game. We made poor decisions and the result was we didn’t come away with the good result.

“We worked on things to simplify the decision making.”

There was no place in the starting XV for flanker David Pocock, who is allowed a further game off to rest a problematic back.

James O’Connor joins Pocock on the sidelines with a hamstring strain, his place taken by the experienced Drew Mitchell.

Rob Horne comes in at centre for Pat McCabe, with fly-half Quade Cooper taking over the kicking duties.

Up front, flankers Ben McCalman and Rocky Elsom, hooker Tafatu Polota-Nau and tighthead prop Ben Alexander are the only forwards to have played against Ireland.

Wycliff Palu will start at No 8, with Nathan Sharpe and Rob Simmons providing an all-new lock pairing.

“It’s our second six-day turnaround in a row so we’re looking to freshen things up a bit,” said coach Deans, dismissing claims that the US team were a “tier-two nation”.

“There’s no such thing – they’re playing in the World Cup,” he said. “We are according the USA full respect by opting for the changes we have made in order to have a totally fresh and focused team.”

Deans said he had not been “shocked” by the Ireland result.

“It was not an experience any of us enjoyed. The key for us now is to be the better for it, by heeding the lessons and acting on them,” he said.

“We were poor in decision-making, discipline, around the contact, and without those three components at a World Cup you’re kidding yourself.

“We’re looking for a better perofmrance from our blokes.

“It’s our third game in 13 days. That’s challenging in itself but not an excuse. But we have to build on that and get some confidence.”

Australia:

15 Kurtley Beale, 14 Adam Ashley-Cooper, 13 Anthony Fainga’a, 12 Rob Horne, 11 Drew Mitchell, 10 Quade Cooper, 9 Will Genia (C), 8 Wycliff Palu, 7 Ben McCalman, 6 Rocky Elsom, 5 Nathan Sharpe, 4 Rob Simmons, 3 Ben Alexander, 2 Tatafu Polota-Nau, 1 James Slipper.
Replacements: 16 Stephen Moore, 17 Sekope Kepu, 18 Dan Vickerman, 19 Radike Samo, 20 Luke Burgess, 21 Berrick Barnes, 22 Pat McCabe.