Kingsley Coman, Ibrahima Konaté and Raphaël Varane trained away from the rest of the France squad as the defending champions tried to deal with a virus that has disrupted their preparations for Sunday’s World Cup final against Argentina.

France, who were without Coman, Dayot Upamecano and Adrien Rabiot because of illness during their semi-final win over Morocco, have implemented hygiene measures in an attempt to ensure more players do not become unwell.

In a situation that brought back unwelcome memories of the Covid-19 pandemic, much of the talk during Friday’s press conference was focused more on social distancing and plenty of hand-washing than on the prospect of facing Lionel Messi.

It is not how Didier Deschamps would have wanted to prepare for the challenge of trying to stop Messi winning the World Cup for the first time. Upamecano and Rabiot have rejoined the main group but Coman, Konaté and Varane were struggling and were forced to train indoors on Friday. The midfielder Aurélien Tchouaméni and the left-back Theo Hernandez also trained indoors because of respective hip and knee problems.

If Konaté and Varane are unfit it would leave Deschamps without two of his three main centre-backs. The duo played well together against Morocco. If they are out then Upamecano, who partnered Varane during the quarter-final win over England, could be accompanied in central defence by Arsenal’s William Saliba, whose only appearance so far was as a substitute in France’s defeat by Tunisia in their final group game.

But Deschamps will not be worried only about his defensive situation. France are trying to contain the virus but the fear is more players could fall ill. That would present Deschamps and a squad deprived of N’Golo Kanté, Christopher Nkunku, Paul Pogba and Karim Benzema by injury before the tournament with a huge problem. Lucas Hernandez is definitely unfit. Suggestions Benzema, who has recovered from a thigh injury, could fly to Qatar and play, as he was never replaced in the squad, remain unconfirmed.

It would be a drastic measure for Deschamps to call upon Benzema. France have coped without the Real Madrid striker, with Olivier Giroud, Kylian Mbappé and Antoine Griezmann excelling in attack. For now their focus is on making sure everyone is healthy in time for the final.

“We’re not scared of that virus,” Ousmane Dembélé said. “Dayot and Adrien had a headache, a bit of a stomach ache. I made them a ginger and honey tea, and then they felt better. I hope everyone will be ready for the final.”

There have been theories that the virus, which has brought on flu symptoms, was picked up during the England game. The England midfielder Declan Rice missed a day of training because of illness last week.

There is nothing to prove that theory, though, and another possible explanation is that France have fallen victim to something that has afflicted many visitors to Qatar during the World Cup. There have been many complaints that air conditioning at stadiums, hotels and media centres has been the cause of sore throats and coughs.

Dembélé, who played with Messi at Barcelona, said France were ready to dash the Argentina captain’s dream. “Messi is a dream to play with,” he said. “In the dressing room he is very modest, he helps the younger players and taught me a lot. It’s difficult to play against him but we will do everything we can.

“We are fighting for our country, for all the French people. We want the French people to be proud of us. It would be great for Lionel to win but we want to win too.”