Marseille have found a fifth asymptomatic case of coronavirus in their squad, a club spokesperson told AFP on Friday, on the same day the new French Ligue 1 season kicked-off under an increasingly darkening COVID-19 cloud.

Andre Villas Boas' squad had been scheduled to open the French season later in the day at home to Saint-Etienne but the game was cancelled after the four earlier positive tests.

The club have not revealed the names of the players but said they are in isolation at home.

The rest of the Marseille squad were given the weekend off ahead of next Sunday's game at Brest.

Hours later, Saint-Etienne said one of their players had also tested positive.

Nantes' trip to Bordeaux was moved from Saturday to replace the season-opening fixture at the Velodrome.

It proved little comfort as the game, the first in the competition in 166 days following the coronavirus lockdown and played behind closed doors, ended in a tame 0-0 draw.

Nantes had a one-man advantage for more than an hour after a 20th-minute red card for Mehdi Zerkane.

The Bordeaux player was punished after a VAR consultation for an ugly lunge into the leg of Nicolas Pallois.

Earlier on Friday, Nice coach Patrick Vieira said he was concerned about the impact two coronavirus cases could have on his club.

Nice said a pair of players had been held out of training and placed in quarantine after contracting the virus.

"I felt on the pitch the rest of the squad is worried. I am too, for the match against Lens on Sunday and for what happens next," Vieira told a press conference.

"It complicates the planning. We'll have to put up with it and be very responsible at home."

Newly-promoted Lens are awaiting the results of further tests after defender Jonathan Clauss returned a positive sample earlier in the week.

"I hope we will play. If we start by postponing the first weekend, we'll get nowhere," said Lens boss Franck Haise.

"I think we need to play as much as we can when it's possible otherwise we're going to finish the season in 2023."

Meanwhile, Nimes announced a fourth coronavirus case within their squad putting Sunday's fixture against Brest at risk.

"I hope we can play it, I think we can play it," the southern side's coach Jerome Arpinon said.

According to a club source captain Anthony Briancon and striker Nolan Roux are among those to have tested positive for the illness.

Brest also recorded a case, saying the individual had been placed in isolation while the rest of the squad and the coaching staff have tested negative.

A 57-page medical and health protocol set up by the French league is designed to limit stoppages and reduce contamination as much as possible.

Players will be tested two to three days before each match and a game will be postponed as soon as four cases are found at the same club within an eight-day period.