Eight Montpellier players and four backroom staff have tested positive for Covid-19, the club said on Friday, putting in doubt their weekend Ligue 1 game against Monaco.
The entire squad underwent further tests on Friday while the 12 who tested positive have been put in isolation, according to the club.
Michel Der Zakarian's team, currently fifth in Ligue 1, are scheduled to play at Monaco on Sunday.
Since the coronavirus pandemic started, seven players at Montpellier tested positive.
Midfielder Junior Sambia, who was hospitalised and put in an artificial coma in April, was the first known Ligue 1 player to have contracted the virus.
The 24-year-old has recovered and has made several appearances for the team in the new season.
