France star Thomas Castaignede has tipped Ireland for the Six Nations Grand Slam if they beat the French at Dublin on Saturday.

"If Ireland beat us on Saturday I'd tip them for the grand slam but if we can win at Lansdowne Road, I'd go for a three-way tie between ourselves, England and the Irish."

France coach Bernard Laporte has to choose between Castaignede and Xavier Garbajosa as his centre pairing when he names his side tomorrow. Castaignede has impressed when he has come on as a substitute, in the defeat to England and the win over Scotland. He fears Ireland have forged a formidable pack and midfield.

"Their front five are the most mobile in the championship. Perhaps they aren't collectively as powerful as France or as experienced as England - but all round they are the best," he said. "Keith Wood's absence is barely noticed."

With regard to David Humphreys, he said: "He will give them opportunities to play a kicking game, which we lacked against England. He organises play well and gets his backs moving sweetly.

"On top of that the Irish are at home at Lansdowne Road and they boast Brian O'Driscoll, the best centre in the world."

Castaignede says England will suffer because of the spate of injuries that has robbed them of their first-choice props and he believes England have yet to find an ideal midfield set-up. "England have so far not looked to be at the same heights they reached last year."

And he thinks England might yet choke again. "Each time England's fingers get burnt. They seem fated to fall down just when the way looks open."

France will be without influential scrumhalf Fabien Galthie against Ireland. He has been replaced by 22-year-old Dimitri Yachvili, whose father Michel won 15 caps for France as hooker or in the back row between 1968 and 1975. Yachvili will form a new half-back pairing with Francois Gelez when he wins his third cap.

Meanwhile, Jonny Wilkinson was last night appointed England captain for Sunday's tie against Italy. Outhalf Wilkinson takes over from Martin Johnson, who was set to celebrate his 33rd birthday by captaining England for the 29th time, but an Achilles injury yesterday dashed those hopes. Wilkinson, England's record scorer with 620 Test points, will skipper his country for the first time.

Woodward is already without the services of Ben Cohen (thigh), Neil Back (calf), Lewis Moody (shoulder), Phil Vickery (back), Jason Leonard (hamstring), Julian White (knee), Iain Balshaw (shoulder), Austin Healey (Achilles) and Mike Catt (hamstring).

Woodward plans to announce the team this afternoon afternoon.