Vunipola out of World Cup

England's stuttering Rugby World Cup has suffered another blow with influential forward Billy Vunipola ruled out of the rest of the tournament following a knee injury.

England's Billy Vunipola tries to charge down a kick from Wales scrum-half Mike Phillips, February, 2015. Photo: PHOTOSPORT

Nick Easter, not selected in Stuart Lancaster's 31-man squad, has been called up as his replacement.

With Ben Morgan a fitness doubt, the 37-year-old Easter could be in line to make his first England start in four years in Sunday's must-win Pool A clash against Australia.

The strong-running and hard-hitting Vunipola suffered a knee ligament strain in the dramatic 28-25 defeat by Wales at Twickenham.

Vunipola, who came off the bench to score a late try to secure a bonus point in the opening win over Fiji, had started against Wales after a knee injury ruled out Morgan.

The Gloucester No.8 had only just returned to the fold after recovering from a broken leg.

"It's so unfortunate for Billy but the scan shows an injury which means he can't take any further part in the World Cup," Lancaster said.

"He has worked really hard and committed everything to the last three months but he is a young man with a bright future ahead of him and I know he will be an integral part of this team for years to come."

Easter, capped 52 times, made his first England appearance since 2011 when he came off the bench against Wales in the Six Nations Championship clash in Cardiff in February.

"Nick was unlucky to miss out on final selection. He is a specialist number eight and an experienced player. We know he will make a big contribution," Lancaster said.

- Reuters