THE injury-ravaged Wallabies are down to their last fit back after centre Scott Staniforth was ruled out of tomorrow's World Cup match against Canada last night.

Staniforth has succumbed to a shoulder injury he sustained in Sunday's 55-12 win over Fiji in Montpellier.

His withdrawal has forced a major backline reshuffle for the Wallabies' final Pool B match against the Canucks in Bordeaux.

Chris Latham comes off the bench to start his fourth straight World Cup match at fullback, pushing Cameron Shepherd onto the wing.

Lote Tuqiri moves from the wing into the centres, joining Adam Ashley-Cooper who takes Staniforth's No. 12 jersey.

Matt Giteau, who the selectors were desperate to rest, now has been promoted to Australia's bench to cover several backline positions.

The Wallabies are expected to make easy work of Canada but the latest injury puts extra pressure on their preparations for a likely quarter-final against England on October 6.

Staniforth joins Stephen Larkham (knee infection) and captain Stirling Mortlock (shoulder) on the sidelines while rookie five-eighth Berrick Barnes has been rested to overcome a quad niggle.

Larkham is aiming for a semi-final return but there are no guarantees. The 102-Test flyhalf was released from hospital yesterday and is on crutches.

AAP