The Saracens star was forced to miss Les Bleus opening two encounters after aggravating a thigh injury but is one of three changes from the side that almost blew a 43-3 lead against Ireland a fortnight ago before hanging on for a 43-31 win.

That followed a shock 20-16 opening weekend defeat to Scotland, which blew the pre-tournament favourites chances of the Grand Slam.

We experienced a tough match against Scotland who have shown the extent of their progress, said Castaignede, who comes in at full-back, with Christophe Dominici switching to wing in place of Cedric Heymans, despite the Toulouse mans two-try show against Ireland.

Against Ireland we played brilliantly for 50 minutes and then, because of the pressure and the lack of concentration we failed to kill the match.

The aftermath of the mini-collapse against Ireland has produced many theories as to what went wrong, but Castaignede reckons the explanation is simple - a lack of confidence in a usually extrovert French side.

He said: I dont think we suffered any physical problems at all, we just completely lost our confidence.

We relaxed in the second half and against players like the Irish, who are very proud, it ended up a weird match even though we won eventually.

The 30-year-old, whose international career has undergone something of a renaissance in recent months, was expected to play in Les Bleus opener at Murrayfield but a niggly thigh injury reared its ugly head again.

It was hard for me to see the team play without me, said Castaignede, who was a key member of Frances successful November Test matches against Australia, Canada, Tonga and South Africa.

It was hard to pull out. I suffered two consecutive problems with my thigh. It got aggravated, I had to make a choice, thats sport.

Castaignede is also adamant that Italy, who are now coached by former France boss Pierre Berbizier, will make it hard for them on Saturday.

I know Pierre Berbizier very well, I have a lot of admiration for him and his career as a player and a coach, Castaignede added.

His qualities are showing on the Italy side, thats exactly what they needed.

I think Italy have now definitely earned their place among the Six Nations. They defeated Argentina, almost won in Ireland and played on even terms with England.

For us, the objective will be to win the match and its not going to be easy because the Italians are a better team.