Montpellier - South Africa's Johan Goosen will be sidelined for up to six weeks with a foot injury, his club Montpellier said on Tuesday.
Goosen, 26, who retired from the sport in 2016 before joining the Top 14 runners up this summer - did not play in last weekend's loss to league leaders Toulouse with the problem.
The 13-time international has already missed a month and a half of the season with an ankle issue.
Struggling Montpellier are at risk of failing to reach the end of season play offs as they sit in a surprising ninth place in the league. Vern Cotter's outfit have already been knocked out of the Champions Cup.
Powerful former Fiji wing Nemani Nadolo has returned to training after sitting out more than six weeks with a knee issue.
However, Nadolo, 31, who announced his retirement from international rugby in January, a matter of months from the Rugby World Cup in Japan, remains a doubt for Saturday's league game against Bordeaux-Begles.
France squad member Yacouba Camara has been released to play for Cotter's side for this weekend's Top 14 match due to the Six Nations' fallow week.