World Cup legend Martin Johnson has urged England to "set the level" when they launch their Webb Ellis Trophy defence against America in Lens tomorrow.

England have slumped to seventh in the world rankings since Johnson held aloft rugby union's glittering golden prize almost four years ago.

Despite the loss of fly-half Jonny Wilkinson to yet another injury setback - this time an ankle ligament sprain that suggests he might play no part in the tournament - England should still swamp the USA ahead of their pivotal Pool A appointment with South Africa at Stade de France next Friday.

For a team that has failed to register a try in its last two Tests, they should at least end that barren sequence by seeing off a team likely to prop up Pool A.

Johnson (pictured at a Visa Rugby Legends media day) said: "The team hasn't played that many matches together.

"On Saturday night, it is important to set the level where they want to be."

And as for England's current lowly global status, he added: "I am not embarrassed.

"We are where we are - we just have to deal with that.

"The great thing about the World Cup is it's the big one. There is no next week, or next year."

Olly Barkley, who made his England debut as a teenager against the USA in San Francisco six years ago, replaces Wilkinson for a game that England's forwards will look to dominate ahead of more serious business against South Africa.

If the anticipated pack supremacy materialises, it will then be a case of shipping possession wide to a dangerous back three of Mark Cueto, Jason Robinson and Josh Lewsey, who wins his 50th cap.

For their part, America have played 151 Tests since USA Rugby was formed in 1975, with their scalps including Samoa, Fiji, Tonga, Canada and Japan.

But they have yet to defeat a leading nation, and can reflect on just two victories in World Cup history - both of those being against the Japanese.

Eagles fly-half and captain Mike Hercus, formerly of Sale Sharks and Llanelli Scarlets, said: "We aim to be the most successful American team ever.

"If we win one game, fantastic. If we win two, we'd be ecstatic.

"England are the current world champions, and we are excited to play one of the best teams in the world. We also know we have a challenge ahead of us, and that it is a massive one."

The improved profile the Eagles enjoyed after qualifying for this year's World Cup followed a concerted 18-month push to promote the sport in the USA.

During that time they appointed a new board of directors and coach, while ex-England captain Nigel Melville, the former rugby director at Wasps and Gloucester, is USA Rugby's chief executive.

And Melville believes a successful World Cup campaign would further boost the profile of the sport in the US.

He said: "There is a great deal of excitement in the rugby community.

"People who normally would steer clear of rugby are becoming interested, and success in France would certainly be a springboard to even more mainstream exposure."

USA coach Peter Thorburn has made one change from the side beaten by Munster's second string in a World Cup warm-up game in Chicago last month, with hooker Owen Lentz replacing Blake Burdette.

Sproting Life / Eurosport