Lancaster’s men stand on the verge of a first Six Nations title in four years.
They are locked on three wins with Ireland and Wales, but have a points advantage of plus-four and plus-25 on their two rivals respectively.
Ireland go to Murrayfield to face Scotland while Wales have arguably the easiest fixture in Rome against an Italy side minus their talisman Sergio Parisse.
England welcome France, traditionally one of the powerhouse fixtures of any Six Nations.
Even though Les Bleus have been more hot and cold than ever in this year’s championship, the statistics tell Lancaster that he will need every last one of his 23-man squad to rise to the occasion at Twickenham tomorrow.
“The last 15 tries France have scored, 11 of them have been in the last 30 minutes of the game,” observed Lancaster, who has made one change to the starting XV that beat Scotland last week, with lock Geoff Parling coming in for Dave Attwood, who drops out of the 23 altogether.
“The bench France bring on – Benjamin Kayser, Uini Atonio, Mathieu Bastareaud – is their strength, as has been shown over the last few weeks, that last 15 to 20 minutes in the game.
“It’s not just about countering that, but having people who will have an impact to come on if you have to chase a game, or if you are trying to get another score.
“That did affect some of the selections, probably at hooker for example and the impact Tom (Youngs) can bring. Nick Easter is an example as well and that is why he is back on the bench.
“Nick has really impressed in camp and in his appearances off the bench.
“Nick is a quality ball carrier and great defender – things we feel we’ll need in the latter stages of the game.
“The bench will be important, but also those players who come on could be involved in the decision-making.
“If Richard Wigglesworth is on at nine, which is likely, then he needs to be able to see out the game, but also understand if we’re seven points adrift with five minutes to go, what we’re going to do about it.”
Tomorrow’s Six Nations decider is also England’s last competitive game before they kick off the World Cup back at Twickenham on Friday, September 18, against Fiji.
Lancaster admits the importance of tomorrow’s game and the prize at stake has given it a World Cup feel.
But, the fact that it is points difference that will decide the outcome of the championship and because England play last tomorrow after Wales have played in Rome and Ireland follow in Edinburgh, leads Lancaster to draw comparisons to golf’s great biennial duel.
“It does feel a bit like I assume a World Cup game will feel like in that it’s a big game where there’s a lot on the line,” said Lancaster.
“But it is different and I can’t think of another situation in sport where you’d go into it with this points differential that can affect the psychology, so it is different to a World Cup.
“The only scenario I can think of that is similar is the final day of a Ryder Cup when you’re ahead or behind when the singles are coming.
“It’s that sort of feeling. It will tell us a lot about the players, but it is a pretty unique situation as well.”
Lancaster has challenged his captain Chris Robshaw to rise to the occasion and lead England to glory.
The former Leeds player and director of rugby has been fulsome in his praise of Robshaw, whose performances through the tournament have helped quieten the clamour for England to break their own code and call-up Toulon openside Steffon Armitage.
Now Lancaster wants Robshaw to put the seal on an impressive championship by lifting the trophy.
The head coach said: “His major contributions have been: one – to maintain his place in the team given the competition for places so that has not been easy for him and, two – as he has grown in confidence he has taken more responsibility.
“He has had some criticism along the way – in certain games some decisions were made – but he has had the strength of character to come through it.
“This game will test him and the other leaders that surround him. There will be decisions to be made that wouldn’t normally have to be made with the potential scenarios that may emerge.”
Explaining the one change he has made, re-introducing Stockton-on-Tees-born lock Parling, 31 – who will win his 23rd cap against France – Lancaster said: “Geoff did well off the bench against Scotland and now that he has got some games under his belt we feel it is the right time to start him and use his experience and quality in the starting line-up.”