Rugby World Cup 2015: Australia lose Will Skelton & Wycliff Palu

Skelton was the second heaviest player at the Rugby World Cup at 140kg and has won 14 caps since making his debut against France in June 2014

Australia have suffered a setback in their preparations for Saturday's Pool A match against England as forwards Will Skelton and Wycliff Palu have been ruled out of the World Cup.

Powerful lock Skelton, 23, sustained a pectoral injury during the Wallabies' 65-3 victory over Uruguay on Sunday.

Number eight Palu, 33, injured his hamstring in the match and will be replaced by hooker James Hanson, 27.

Lock Sam Carter, 26, will replace Skelton in the squad.

Australia coach Michael Cheika told the team's official website: "Very few players have the opportunity to play for the Wallabies, let alone at a Rugby World Cup, so I'm really gutted for them.

"They both play important roles in the side and it is disappointing that we need to replace players.

"James and Sam have been part of the team at various stages this season and I am confident they will be able to step up and grasp the opportunity."

Australia, who comfortably won their opening game against Fiji 28-13, face their first major test on Saturday when they play England at Twickenham in a must-win match for Stuart Lancaster's side.

Coach Cheika surprised many by only naming two hookers in his 31-man squad, but has decided not to replace Palu with another back-rower, instead calling on Hanson, who flew out from Australia on Monday.

Cheika said Palu's injury meant the 33-year-old had "likely" played his final game for the Wallabies as he has signed to play in Japan next season and falls three caps short of Australia's 60-cap threshold for overseas-based internationals.

Cheika said he was not thinking about finishing top of Pool A

The loss of New South Wales Waratahs player Skelton, who weighing 140kg was the second heaviest player at the tournament, is a significant one for Australia as his ball-carrying ability will be missed.

Cheika said unbeaten Wallabies were underdogs for the Twickenham match, which England must win if they are to qualify from Pool A.

"We're playing in the oppositions back yard," he said. "They've been very successful at that ground. It's just about being ready to be ourselves and play the best we possibly can.

"Every team has the ability to bounce back. We've been in the same position. I'm sure they'll believe strongly they can beat us."