By Bryn Palmer
BBC Sport in Paris
I know I have my job to do and I know I am capable of doing it
England legend Martin Johnson believes Tom Rees can develop into a world-class flanker as the current side prepare to begin their World Cup trophy defence.
The open-side flanker has won six caps and started just three Tests to date.
"Tom is an inexperienced player in Test terms but has played very well in European games for Wasps," he said.
"There's a lot of responsibility for a guy who hasn't played many games but I think he'll come out of this tournament as a world-class number seven."
The world-class open-side flanker in the team Johnson captained to World Cup glory in 2003 was Neil Back, and Rees acknowledged that he would be trying to follow in the Leicester stalwart's footsteps.
"Neil Back changed the way the modern number seven played - as a young player, I have to aspire to that level," Rees told BBC 5live.
"In terms of pressure I know I have my job to do and I know I am capable of doing it. I have to concentrate on performing my role."
Rees missed two of England's three warm-up games because of injury, and he acknowledged that the whole team needed to improve on those displays.
We haven't had enough guys coming through who can go on to become world-class players - but Tom Rees is one
Former England captain Martin Johnson
"We know as a team from the way we performed in the warm-up games that there is ground to be made up," said Rees.
"We always said warm-up games were exactly that. There was a lot of experimentation - they were like pre-season games."
England go into the World Cup on the back of five defeats in six games, and Rees said it was vital that the players swiftly regained the winning habit against a team ranked 15th in the world.
"We have got videos of the USA and information on their individuals," he said.
"We must respect them but we have to get on with the game and show that, as one of the nations with ambitions of winning the tournament, we can stamp our authority all over the game."
Rees, who turns 23 next week, is the youngest member of the England team aiming to produce a commanding victory against the Americans in Lens on Saturday.
"I am a little bit concerned about the lack of young guys who have come through to establish themselves," added Johnson.
"That's partly down to inconsistency of selection and of performance, but we haven't had enough guys coming through in the last four years who can go on to become world-class players. But Tom Rees is one."
If it wasn't for the ankle injury that has sidelined the luckless Jonny Wilkinson, Rees would have been almost five years younger than any other player in the side.
As it is, Olly Barkley, 25, has brought the average age of the side down to just over 30.
"We all wish Jonny's injury hadn't happened and we hope he will be back for the South Africa game," Johnson added.
"But Olly Barkley is a very good player and maybe it is his time to step up and take his chance now.
"If Jonny doesn't make it, there is no bigger game than a World Cup pool match against South Africa to show what you're made of."