France scrum-half Antoine Dupont has tested positive for Covid-19, just over a week before the Six Nations meeting with Scotland in Paris.
Dupont, Six Nations player of the year in 2020, missed the wins over Italy and Ireland with a hamstring problem.
The French Rugby Federation announced its positive test on Friday, with 11 other players testing negative.
All members of the 31-man squad have been tested, with the other results not yet known.
Head coach Fabien Galthie and assistant William Servat tested positive earlier this week and have been isolating.
French Health Minister Olivier Veran announced on Thursday that anyone testing positive would need to remain out of contact with others for 10 days, up from seven.
A replacement for Lyon forward Dupont has yet to be named, with France recalling tighthead prop Demba Bamba following injury.
Les Bleus, top of the Six Nations table and aiming for a first title since 2010, have made two other squad changes, with Toulon duo Jean-Baptiste Gros and Swan Rebbadj also included.
Dorian Aldegheri drops out following Bamba’s return, with Baptiste Pesenti and Hassane Kolingar the others making way.