Australia's chances of toppling Argentina in Sunday's World Cup semi-final improved after David Pocock and Israel Folau were passed fit and named to start at Twickenham.

The pair were injured during the final group outing against Wales and were forced to sit out the 35-34 victory over Scotland, but have recovered from their respective calf and ankle problems.

Pocock has been among the players of the tournament - the number eight was a key component of the win against England - and Folau is one of the sport's most dangerous runners from full-back.

Ben McCalman and Kurtley Beale drop to the bench to make room for the returning duo.

The only disappointing element of an otherwise pleasing injury bulletin from Friday morning's training session was prop Scott Sio's failure to recover from his elbow complaint, so James Slipper starts at loosehead.

"James has been pushing for a starting spot with his performances as a finisher and I know he'll take it with both hands," head coach Michael Cheika said.

"James is a leader in our squad and has performed well through this tournament so far and in the lead-up matches.

"This weekend is a great opportunity for the lads to improve on last week and take advantage of the chance to play on such a big stage. This weekend we want to make Australia proud of their team."

Openside Michael Hooper will make his 50th Test appearance and wing Drew Mitchell is just one try short of drawing level with Bryan Habana and Jonah Lomu as the leading World Cup leading try-scorer of all time.

Australia: I Folau; A Ashley-Cooper, T Kuridrani, M Giteau, D Mitchell; B Foley, W Genia; J Slipper, S Moore (capt), S Kepu, K Douglas, R Simmons, S Fardy, M Hooper, D Pocock

Replacements: T Polota-Nau, T Smith, G Holmes, D Mumm, B McCalman, N Phipps, M Toomua, K Beale