Three Paris St-Germain players have tested positive for coronavirus, the Ligue 1 club said on Wednesday.
The French champions, who lost in the Champions League final last month, have not revealed the players involved.
"All of the players and coaching staff will continue to undergo tests in the coming days," a club statement said.
The French league is already under way but PSG are due to start their title defence at Racing Lens on 10 September after being given an extended break.
The opening game of the Ligue 1 season between Marseille and Saint-Etienne had to be postponed last month after four home players tested positive for Covid-19.
The French league told clubs last week its protocol for dealing with coronavirus meant more than three positive cases at a club was likely to lead to a postponement.
The 2019-20 campaign was curtailed in April because of the Covid-19 pandemic, with Paris St-Germain, 12 points clear at the top, awarded the title.