The Swiss have never won the Davis Cup in its long history, while France have won the team trophy nine times, the last coming away to Australia in 2001.

Federer is a 17-time Grand Slam winner and currently ranked second in the world, while this year's Australian Open champion Wawrinka is ranked fourth.

Logically they are the hot favourites -- but a dramatic weekend in London at the season-ending ATP World Tour Finals has changed the picture.

That was due to a remarkable semifinal that pitted the two Swiss players against each other and which Federer won after saving four match points in a gruelling blockbuster that lasted just short of three hours.

The duel left both players bruised and battered. Wawrinka was distraught at letting slip such a golden opportunity to better, for once, his more illustrious countryman.

Federer was left in such pain from back spasms that he was forced to forfeit the next day the tournament final against Novak Djokovic.

If that was not damaging enough, the two Swiss stars found themselves embroiled in an ugly spat over an incident late in the third set of their match when Wawrinka complained about noises coming from Federer's courtside box, with his wife Mirka being the culprit.

By all accounts the two had a long and tense set-to in the locker-room afterwards and they made their own separate ways to Lille on Monday.

Since then the Swiss players have been at pains to play down the incident appearing at a press conference during which they laughed and traded jokes and jibes.

More worryingly for the Swiss though has been the state of Federer's back -- an injury which has increasingly nagged him in the later years of his career.

He was unable to practice on the red claycourt that has been painstakingly laid down inside one half of the Stade Pierre Mauroy football stadium outside Lille, until a brief 30 minutes outing on Wednesday evening.

During that stint, he looked tentative, especially on serve and Federer himself admitted he can only take it one day at a time.

"I'm making some progress. But I know I don't have a month ahead of me to get better. I need to get better quickly. I'm trying whatever I can," he said Tuesday evening.

The problem for the Swiss is that although Wawrinka is comfortably ranked above all the French players, after him the fall-off in the Swiss team is steep with Marco Chiudinelli 212th and Michael Lammer 508th in the rankings.

Without Federer, their chances of winning the Davis Cup for the first time look slim, with the French boasting a strength-in-depth line-up of Jo-Wilfried Tsonga, Gael Monfils, Richard Gasquet and Julien Benneteau.

There was speculation that the Swiss team may decide not to take the risk of playing Federer on Friday and rest him up for Sunday and the reverse singles rubbers, hoping that Wawrinka can keep the final alive in the first two days.

In contrast, the French team's preparation for the final has been flawless, helped by the fact that none of the team qualified for the London ATP finals.

They spent 10 days cloistered down in Bordeaux, practicing on clay, away from the spotlight.

French captain Arnaud Clement said that his team were not even considering contesting the Davis Cup final without the presence of Federer.

"We have been preparing for the last 10 days to play against a Swiss team with Federer and Wawrinka in it," he said.

Clement said that he had yet to decide who would play the opening two singles on Friday, but Tsonga looks sure to be top choice with Gasquet slightly ahead of Monfils for the second slot.

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