Argentina will try and target the Australia scrum with powerful prop Scott Sio sidelined with injury.
There must be a pep in the Gold and Green step with the return to fitness of brilliant Number Eight David Pocock and Full-Back Israel Folau. While all week, focus will have been drilled into their minds not just because of their own so nearly costly lapses against Scotland last Sunday, but because of Argentina's fast start and clinical finish against Ireland. There will be no expectations of gifts from the Pumas like South Africa received in the 2007 semi-finals or 60-minute shifts like the South Americans managed against the All Blacks in the 2011 quarter-finals and again on the first Sunday of pool action.
Argentina will try and target the Australia scrum with powerful prop Scott Sio sidelined by an elbow injury but Sio's technique came under scrutiny against Scotland so there might have been a change there anyway with Jamie Slipper offering plenty in the loose and enough nous to be competitive for long periods. And the Aussie scrum stood up to the tests of England and Wales well in the pool stages. It will also be interesting to see just how fit Argentina skipper Agustin Creevy is after his leg injury.
The Pumas will probably keep trying to involve their flying back three of Juan Imhoff, Santiago Cordero and Joaquín Tuculet at every opportunity. And while this should mean plenty of opportunities for points, the approach arguably let Ireland get a foothold in last Sunday's game and the Wallabies will relish an open contest too with their full set of strike runners.
Australia avenged last year's 21-17 loss in Mendoza with a 34-9 success at the same venue in July and the points totals of the previous five Rugby Championship meetings, all won by the Wallabies, were 57, 71, 27, 44 and 42.
Australia wingers Adam Ashley-Cooper and Drew Mitchell have been the silent assassins of this World Cup - indeed Mitchell (14) is pushing to join Jonah Lomu and Bryan Habana on 15 career World Cup tries - and Pocock has become the driving force of their rolling maul, but the picks for anytime tryscorer bets are Tevita Kuridrani at 9-2 and Michael Hooper at 6-1.
Outside Centre Kuridrani acts as a battering ram close to the line off rucks as well as a midfield-breaker and has scored tries in his last two outings against Argentina.
Hooper took over from Pocock as the boss of Australia's forward moves against Scotland and scored a try and while he may revert to a supporting role again, he has crossed the tryline on several other occasions too including against South Africa in July and the Pumas last year. Hooper scored two in the 32-25 Gold Coast win.