Martin Johnson could be involved in England's 2007 World Cup campaign - as part of the coaching staff.

Although England's defence of the Webb Ellis Trophy is more than three years away, retired skipper Johnson would appear an obvious candidate to join Sir Clive Woodward's backroom team.

Johnson's immediate playing career will revolve exclusively around his club Leicester, having called time on an 84-cap international chapter which saw him lead England to World Cup and Six Nations Grand Slam glory.

Woodward has already expressed a hope that Johnson could have a future role within the international set-up.

Johnson said: ''If England want me involved at some future date, we can talk about it, but right now, I want to concentrate on Leicester.''

Woodward prides himself on the quality of his coaching support staff, and the likes of Andy Robinson, Phil Larder, Dave Alred and Dave Reddin were key influences during England's World Cup triumph in Australia.

Johnson, given the respect he commands, coupled with an astute knowledge of the game, would prove an outstanding addition.

The 33-year-old paid tribute to the ''great players, teams and coaches'' he had been involved with after confirming rugby's worst-kept secret that he was leaving the Test match arena following an international career that began in 1993.

''You know when it's time, you know yourself it's the right time,'' said Johnson.

''I've had a great career and been very lucky to play with great players, teams and coaches through the years.

''It's time to call it a day. You never want to not play for England, you're always going to miss it, but you have to be sensible and realistic and I just think it's the right thing to do.

''You know in your heart of hearts when it's time to go. It's not about numbers and getting caps - if it's time to go, it's time to go.

''I've made the decision, and I think I've made the right one. I was thinking about it post-World Cup. I rang Clive and explained my feelings, and I gradually realised I wasn't going to change my mind.

''There have been many highlights - the Grand Slam, winning the World Cup - but most of all, I will remember the moments together as a squad, just before and just after matches, in the changing room.

''I would like to thank Clive and the other coaches who have worked with me since I made my debut, the guys I have played with and the fans who have followed us around the world.''

Johnson skippered his country 39 times and captained the Lions to South Africa in 1997 and Australia four years later.

Johnson will continue playing for Leicester, but his England era is over, ended by unforgettably lifting the Webb Ellis Trophy.

Leicester rugby director Dean Richards, a former England team-mate of Johnson's, offered glowing praise of Tigers' talisman.

''Even with intense media focus and adulation falling on him after his team's wonderful achievement in Australia recently, he has remained the same humble and level-headed character he was when he first came to the club as a youngster,'' Richards said.

''With Martin's retirement from international rugby, England is not only losing a great captain and player, but a man who typifies the spirit of the game.''

Tigers' chief executive Peter Wheeler added: ''Martin and his achievements have been colossal.

''I do not think that we quite appreciate at the moment the enormity of what he has done, and in years to come, we will look back and realise that it was more than we ever thought.''

Tigers chairman Peter Tom said: ''He has been the best possible ambassador for Leicester throughout his international career, and every one of our supporters is extremely proud of what he has achieved.

''However, England's loss is Leicester's gain, and we hope that he will continue to play for us and be involved with the club for many years to come.''