Lawrence Dallaglio expects Martin Johnson to be as competitive as ever when the pair are reunited for the 'Help for Heroes' match at Twickenham.
The England legends have been lured out of retirement to play in the September 20 fundraiser staged to help the care and rehabilitation of British service personnel injured in Iraq and Afghanistan.
It will be the first time they have featured together in the same side since the 2003 World Cup triumph.
But Dallaglio is confident inactivity will not have sapped the will to win of England's new team manager, who finally hung up his boots three years ago.
"I've spoken to Martin about the match and he's looking forward to it," he said.
"He's got his hands full running the England team so it will be good for him to be able to play a game at Twickenham without having to worry about who is selecting the team.
"Being the competitive animal that he is, Martin has been working hard to ensure he will do himself justice on the pitch. He has kept himself fit.
"We haven't played together since the World Cup final but this will definitely be the last time!"
Dallaglio will lead the Heroes XV against Scott Gibbs' Select XV with some of the sport's biggest names agreeing to play in a match which has already sold 30,000 tickets.
New Zealand great Jonah Lomu and Will Greenwood, another of England's World Cup winners, will be present alongside players representing the armed forces.
"There has always been a very close affinity between rugby and the armed forces," said Dallaglio.
"The two share a history that goes back a long way and throughout my career I've had correspondence from servicemen and women who have been serving on the front line.
"The realities of war mean there are not always happy endings to the stories.
"But what is clear is the incredible amounts of courage they have shown.
"Sportsmen and women are often put on pedestals as being heroes of our time but the real heroes are the ones who risk their lives for the benefit of the UK.
"The letters I've had have often talked in glowing terms about the joy rugby has brought. There is a lot of mutual respect between rugby and the armed forces.
"There are a lot of shared values such as the team ethic, the pursuit of excellence and looking after each other.
"It's an incredibly worthwhile cause and as players we're only too happy to show the respect we have for servicemen and women by getting involved.
"I was very happy with the way my rugby career finished at Twickenham last May, but this is a great opportunity for me to do something special for charity."
The aim of the match is to raise £1million for ‘Help for Heroes’ and Dallaglio hopes the attendance will reach 60,000.
"Everyone has put their best foot forward, from the players to the Rugby Football Union who have allowed us to use Twickenham for free," he said.
"I would implore members of the public to do the same by buying a ticket as it's such a worthy charity."