Captain Phil Vickery says the pressure is really on England's players as coach Brian Ashton prepares to cut 10 of them from his final World Cup squad.
Vickery says Saturday's clash with Wales is a "full-on Test match"
"There are a lot of apprehensive people around," Vickery told BBC Sport ahead of Saturday's Test with Wales, one of only two before the final 30 is named.
"Everyone knows they are playing for selection for the World Cup.
"For some guys this could be the only opportunity they'll have to prove to Brian what they are worth."
Saturday's match with Wales at Twickenham is one of three warm-up games for England before the World Cup kicks off in Paris on 7 September.
After the Welsh clash, they take on France twice - at Twickenham on 11 August and in Marseille a week later - before beginning their defence of their title with a pool game against the USA on 8 September.
Ashton will have cut his squad to 30 by the time England meet France for the second time - meaning 10 players are facing World Cup heartbreak.
"You can't dress it up," Vickery said. "It's going to very, very emotional for some guys and there are going to be some very disappointed people.
It's going to very very emotional for some guys and there are going to be some very disappointed people
"But that's life and this is the game and environment we are in.
"It's a lot of pressure on the guys going out on the field but ultimately we are playing Test match rugby and, playing for your country, you are all under pressure."
Vickery expects the game against Wales to be a very passionate affair and dismisses talk that it is just a warm-up game.
"It's a full-on Test match," he said. "You can't really experiment at Test level and England-Wales games are certainly not experimental games."
Ashton has made several changes for Saturday's match.
The most significant see Joe Worsley move to open-side flanker, Martin Corry play on the blind-side, and Andy Farrell return at inside centre in a new-look pairing with Leicester's Dan Hipkiss.