The Wallabies have been dealt a massive blow in the build-up to their crucial World Cup game against England with the withdrawal of barnstorming forwards Wycliff Palu and Will Skelton due to injury.

The loss of such powerful ball runners is not only a blow for the Wallabies prospects against England who they play on Saturday night (Sunday AEST), but their entire World Cup with their final pool game against Wales next week.

Backrower Palu (hamstring) and Skelton (pectoral) - who is the second heaviest player of the tournament - will be returning to Australia immediately.

While Palu had a hamstring concern before the last Sunday's game against Uruguay, both players fates were sealed in the 11-try thrashing of the South American minnows.

Meanwhile, replacing the two forwards will be James Hanson, who is currently in Australia, and Sam Carter who is in France on a playing contract with Bordeaux-Begles.

Carter, who missed out on the Wallabies 31-man squad due to a knee injury, is back to full fitness - but went to Bordeaux-Begles on a four game deal - a move which has now proved to have been wise.

Hanson, a hooker, is in Australia. His call-up means that the Wallabies will at least now have three specialist hookers in the squad, the two others being captain Stephen Moore and Tatafu Polota-Nau.