Lille midfielders Renato Sanches, Jonathan Ikone and Jonathan Bamba have tested positive for Covid-19, coach Christophe Galtier said on Saturday, calling for more firmness in enforcing social distancing.
All three tested positive last Monday, Galtier said after a 2-1 friendly win at Belgian first-division club Mouscron.
He said Sanches, a Euro 2016 winner, had returned to Portugal during a week off and there shown symptoms and tested positive.
"Renato is still in Portugal and he cannot travel yet because he has to pass two negative tests," Galtier said.
He said Ikone, a French international, and Bamba, a France under-21 player, had been confined to their homes but "should come back to training on Monday".
Galtier urged the French to follow the rules on social distancing.
"I've had eight days off and I've seen how we behave," he said.
"Let's continue like this and we'll all be reconfined and it'll be a mess. It's up to the state to be firm.
"If we continue like this, we won't be able to avoid a second wave."