Jason Leonard's landmark 100th England cap should be confirmed on Monday - but probably not in his familiar position of loosehead prop.

England boss Clive Woodward is poised to make 34-year-old Leonard only the third member of rugby union's most exclusive club, joining fellow centurions, Frenchman Philippe Sella and Australian David Campese.

Front-row injury problems mean Leonard looks set for a switch of roles against opening RBS 6 Nations opponents France at Twickenham next Saturday.

Regular tighthead Phil Vickery is sidelined through back trouble, while Julian White's knee problem threatens to keep him out. Alternative candidates Trevor Woodman and David Flatman are both injured.

Against that backdrop, Woodward's team - scheduled to be announced tomorrow afternoon - could see Leonard wearing the number three jersey, with Leicester prop Graham Rowntree recalled for his 39th cap.

Woodward might consider promoting uncapped Northampton tighthead Robbie Morris, but a gamble on such inexperience appears unlikely, given the magnitude of England's task.

It will be Leonard's 15th appearance against France - he has been on the winning side nine times - and culminates a remarkable Test career which began in Buenos Aires more than 12 years ago.

And the Harlequins forward will also set another record, overtaking Rory Underwood's 50-game feat of most Five/Six Nations Championship appearances by an England player.

Elsewhere, Gloucester wing James Simpson-Daniel should return after missing England's record 53-3 romp against South Africa in November because of glandular fever, while either Neil Back or Lawrence Dallaglio are likely to miss out in the back-row equation.

Dallaglio started against New Zealand three months ago, with Back on the bench, but their roles were then switched for England's subsequent games against Australia and South Africa.

England captain Martin Johnson, meanwhile, goes into the France clash knowing that he faces a one-match ban.

Fortunately for Woodward, Johnson's enforced rest will be in domestic rugby - possibly next month's Powergen Cup semi-final clash between Leicester and Gloucester.

Johnson received his third yellow card inside 12 months during Leicester's Zurich Premiership triumph against Bristol Shoguns yesterday, meaning an automatic suspension.

Referee Robin Goodliffe cautioned Johnson for a professional foul, but Tigers boss Dean Richards leapt to his skipper's defence.

"I think that Martin is refereed differently to other players," said Richards. "I don't think any other player would have been given a yellow card for that.

"It goes with the territory, but it shouldn't. Everyone should be treated fairly.

"The other day, Martin took three punches on the chin by someone at Harlequins, and the guy hasn't been cited. You only have to look back 12 months to see Martin cited for throwing one punch at someone else."