In typically no-nonsense fashion, Will Genia has delivered his first captain's instructions as the Wallabies' Rugby World Cup hopes go on the line against the USA on Friday night.

Australia are raging hot favourites to trounce the second-string Americans, but that hasn't stopped Genia from getting the message across to his do-or-die teammates - loud and clear.

"He made it clear what he wants," prop Ben Alexander said.

"As halfbacks want, they want good quick ball, something we didn't give him last weekend.

"So as forwards, we know what he wants. What he tells the backs is probably different, but he tells us 'piggies' to get our act together and make sure we speed the ball up for the backs."

Genia will deputise for resting skipper James Horwill at Wellington's Cake Tin and his Queensland Reds teammate Anthony Faingaa, who will line up at outside centre, says the Wallabies are in safe hands.

"Will takes on a role that he already has in the team. He's got a great aura about him and he's someone who really speaks well in the huddle and James Horwill leads by example," Faingaa said.

"Will leading us out is going to be a fantastic opportunity and a memorable moment for himself.

"He's going to be a fantastic captain, so I will be proud to be led out by Will."

Coach Robbie Deans is demanding a smarter display from his players than what they produced in last Saturday's shock 15-6 loss to Ireland in Auckland.

Playmaker Quade Cooper has been told to rein in the flamboyance and take control with better decision-making, while the scrum must lift their act after conceding five costly penalties against the Irish.

Faingaa has full faith in Cooper's ability to play more conservatively when required.

"Quade does have that game," Faingaa said.

"He can play territory and we did it throughout the whole year (with the Reds), so it's just pulling that out of his toolbox."

Bookmakers have handed the USA a massive 62.5 points start and Australia are expected to put at least 50 on the Eagles to all but seal their passage to the quarter-finals.

A Wallabies win on Friday night and another over Russia on Saturday week in Nelson is likely to set up a quarter-final knockout showdown with South Africa in Wellington on October 9.

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