Morgan Parra and Remi Lamerat are among a quartet of Clermont Auvergne players who are injury concerns following their European Champions Cup semi-final win over Leinster on Sunday.
Scrum-half Parra suffered a thigh problem during the Top 14 side's 27-22 success at Matmut Stadium de Gerland.
Parra, capped 66 times by France, will miss the trip to Lyon this weekend and Clermont are waiting to discover how long he will be out for, with a Champions Cup showdown with defending champions Saracens to come two weeks on Saturday.
Les Bleus centre Lamerat will also play no part in the Top 14 encounter at Lyon after taking a blow to the knee and it remains to be seen how long he will be sidelined.
Fellow centre Aurelien Rougerie is another player who will not feature this weekend due to a foot injury sustained in a triumph over the Pro12 side, which came at a cost.
The same goes for Georgian prop Davit Zirakashvili, who is nursing an ankle complaint, but his compatriot Viktor Kolelishvili is available after coming through the concussion protocol.