Marcoussis - When Camille Lopez takes the field against South Africa on Saturday with the number 10 emblazoned across the back of his French jersey, a nation will hold its breath.

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The 29-year-old Clermont flyhalf, who is back with the Bleus 18 painful months after playing the last of his 16 Tests, has been dubbed the saviour as France tries to find the key to unlock its true potential ahead of next year's World Cup in Japan.

"Camille Lopez is the best flyhalf in France," said coach Jacques Brunel with characteristic candour when he announced the squad for the November Tests.

But - there is always a 'but' with Lopez - there is the question of "the ankle". Can it withstand the rigours of Test rugby, especially against the supremely physical Springboks?

"I have a piece of wood instead of the ankle," Lopez told AFP.

Having missed the 2017 tour to South Africa on medical advice, Lopez lined up against Northampton in the Champions Cup last October keen to impress then-coach Guy Noves who was about to name his November squad.

As Lopez made one of his trademark darting runs through the middle, he was caught and dragged down by his opposite number Nic Groom who then landed on top of the Frenchman. His ankle snapped.

"It was worse than the crusaders," says Lopez.

"I had a fracture of the fibula and the left malleolus with a ruptured ligament. The worst was my ankle. It took me almost ten months to play rugby properly.

"To be injured the week before the announcement of the squad for the autumn Tests was a big slap in the face because in this France team time moves on. What made it tougher was knowing I was out of the Six Nations as well."

It was a big slap in the face for Noves too who watched his side lose to New Zealand and South Africa before being held to a draw by Japan.

In December, Noves was replaced by Jacques Brunel who, with Lopez on crutches, handed the number 10 jersey to Matthieu Jalibert, Anthony Belleau, Lionel Beauxis and Francois Trinh-Duc.

Belleau then went on to start all three Tests on the tour to New Zealand with Jules Plisson as his understudy.

Five flyhalves in 14 Tests is hardly a recipe for stability and team-building ahead of the World Cup which makes Saturday's match a key moment both for Brunel and for Lopez as he tries to atone for the gaps in his international career.

He remains bitter over his omission from the 2015 World Cup squad - "I was screwed" - and is desperate to get to Japan.

Everything, though, will depend on that left ankle.

"At times, it's complicated," he says.

"There are days with pain and days without, I'm aware of it now. I'm prepared because I was told that it would be like that but today I can play normally and do almost anything on the field."

Brunel and a nation of French rugby fans will be hoping that "everything" includes delivering victory over the Boks.