England's Delon Armitage feels Saturday's game against Scotland is "the biggest game of his career".
Victory for Martin Johnson's side would confirm their progress as Pool B winners, while Scotland realistically need to win by eight or more points.
"They are dangerous but we are in the same situation," said Armitage, who replaces Mark Cueto on the left wing in the England side.
"Every year they come and try and turn us over. We will be ready for it."
With Argentina likely to get a bonus-point win over Georgia, England would be eliminated if Scotland scored four tries in winning were they not to get a losing bonus point themselves in the Group B game in Auckland.
Losing teams get a bonus point at the Rugby World Cup for being beaten by a maximum of seven points.
"We are not thinking about what might happen," Armitage insisted.
"We are just thinking about playing Scotland and trying to get the result.
"Our focus is going in there ready to play a Test match against a tough Scotland team who need to win. We have to be ready for it."
Armitage was on the bench for the Romania match which saw Johnson's first-choice back three of Cueto, Chris Ashton and Ben Foden reunited.
"I am very pleased with my form. There is still a lot more to come," said Armitage, speaking ahead of the news that he had been picked to face Scotland. "It was tough sitting on the bench against Romania, watching the two wings score a hat-trick and Foden getting over the line.
"I have been working very hard in the games before that and hopefully I get a run.
"If not, as long as England are doing well, the guys are scoring tries and we are winning that is all that matters."