Australia's McMahon in as straight swap for Hooper; Folau fit

Australia coach Michael Cheika has stuck with two openside specialists in his back row for their Rugby World Cup Pool A showdown with Wales, bringing in Sean McMahon for the banned Michael Hooper in one of three changes to his side.

Saturday's Twickenham clash will decide which of the two countries tops the pool and avoids twice champions South Africa in the last eight, as well as a potential semi-final against the All Blacks.

Cheika was forced to rejig his back row after Hooper was handed a week's ban for charging into a ruck shoulder first to clear out England fullback Mike Brown last Saturday.

McMahon, who was outstanding when Australia's second string pummelled Uruguay in their second pool match, comes in as a like-for-like replacement for Hooper while fellow openside flanker David Pocock again fills the number eight shirt.

Wales coach Warren Gatland has also selected two openside flankers, with Justin Tipuric joining captain Sam Warburton in their back row.

Wallabies winger Rob Horne was ruled out of Saturday's match after damaging his shoulder in the 33-13 victory over England, which secured passage to the quarter-finals for both Australia and Wales.

His replacement Drew Mitchell brings another 66 caps of experience to the backline while the third change promotes lock Dean Mumm from the bench in place of the usual lineout caller Rob Simmons.

The Australians delayed their team announcement because of concerns over the fitness of Israel Folau, who rolled his ankle against England, but the fullback was cleared to start after successfully coming through training on Thursday.

"Every match in this tournament has required our team to step up to another level and we'll need to do that again against an undefeated Welsh team," Cheika said.

"Every player in our squad knows the improvements required, and we still have two days to continue to make them, both individually and as a team."

Team: 1-Scott Sio, 2-Stephen Moore (captain), 3-Sekope Kepu, 4-Kane Douglas, 5-Dean Mumm, 6-Scott Fardy, 7-Sean McMahon, 8-David Pocock, 9-Will Genia, 10-Bernard Foley, 11-Drew Mitchell, 12-Matt Giteau, 13-Tevita Kuridrani, 14-Adam Ashley-Cooper, 15-Israel Folau

Replacements: 16-Tatafu Polota-Nau, 17-James Slipper, 18-Greg Holmes, 19-Rob Simmons, 20-Ben McCalman, 21-Nick Phipps, 22-Matt Toomua, 23-Kurtley Beale

(Reporting by Nick Mulvenney; Editing by David Goodman)