Bernard Foley admits there's extra pressure as he prepares to stake his claim to be the Wallabies' World Cup playmaker in Saturday's Test against Argentina.

Last year's regular choice, Foley has been handed the No 10 jersey for the Rugby Championship clash in Mendoza, relegating Quade Cooper to the bench.

Foley was impressed by Cooper's offering in the Wallabies' opening win over South Africa in Brisbane last weekend.

And he dismisses any notion that he and NSW Waratahs teammate Nick Phipps - reunited for the Argentina Test - are coach Michael Cheika's first-choice halves pairing, ahead of 2011 World Cup veterans Cooper and Will Genia, who started against the Springboks.

"I think Cheik plays his cards pretty close to his chest and he wanted to try both combinations and it definitely worked for them against South Africa," said Foley on Wednesday, admitting he was hurt to be left out of that squad.

The Waratahs star believed it was far from a two-man race with Matt Giteau, Kurtley Beale and Christian Leali'ifano also potential contenders for the No 10 jersey.

He said the in-house competition had taken training to a new level, and is healthy.

The change at five-eighth is one of seven to the run-on side for the Pumas Test with Cheika overhauling his team as he continues to search for his best line-up ahead of the two Bledisloe Cup clashes with New Zealand and then the World Cup.

David Pocock has won this round's battle for the openside flanker role, relegating fellow former captain Michael Hooper to the bench.

Cheika resisted the temptation to start his two world-class fetchers - Pocock and Hooper - together in his backrow and recalled Ben McCalman at No 8 in place of Scott Higginbotham, who drops out of the match squad.

In the other change to the starting pack, renowned scrummager Greg Holmes get his first Test start in eight years, replacing prop Sekope Kepu, who also returns to the bench.

Phipps takes over from the injured Will Genia while Joe Tomane is the injured Rob Horne's wing replacement.

Matt Toomua will start at inside centre in place of Matt Giteau, who is also out injured. - AAP