Defence coach Mike Ford says England face a stern test in the group stage of the Rugby World Cup but that it could serve them well for later in the event.
"You don't want to go to a quarter-final winning by 100 points in every game," Ford said of Group B, which pairs England with Argentina, Scotland, Georgia and Romania.
"If you are not on your game in this tournament you will probably lose.
"We are probably in the group of death as Scotland are playing very well."
Adding that captain Lewis Moody and scrum-half Ben Youngs could play in the opening match against the Pumas having been injury doubts, Ford said: "If we don't treat Argentina with the utmost respect we will come unstuck."
Martin Johnson's side won their final warm-up game 20-9 against Ireland, a match that Ford saw as perfect preparation for the challenges ahead during a tournament that finishes on 23 October.
"It is about being hardened. The last game we played was perfect for us to be ready for a real tough game in that first one," he said.
Captain Moody damaged knee ligaments in January and then suffered a recurrence of the injury in England's first warm-up international against Wales.
Youngs injured his knee during a wrestling session early in England's training camp but revealed he has been fit to play for the last three weeks.
"The aim was to get fit for the second Welsh game, which I was, and also to be available for the Irish game, which I was, but they didn't want to play me," said Youngs.
England's bid to match their 2003 World Cup triumph has been backed by All Blacks assistant coach Wayne Smith.
The former Northampton Saints coach has been impressed with the way Johnson has improved the fortunes of the team since he took over in April 2008.
"They were brilliant. Martin Johnson has done a really good job. He's given them a lot of belief. They come out here with a squad that has developed its game hugely from basically a 10-man rugby team to playing 15-man rugby.
"I think that makes them a real danger."