Clermont back Zac Guildford is facing three to four weeks out after being violently attacked late on Saturday night.
Clermont's 77-game home unbeaten streak came to an end as Castres claimed a hard-fought 22-16 win in Saturday's Top 14 play-off.
The Ligue Nationale de Rugby (LNR) has announced several changes to the Top 14 competition that will kick in from next season.
Saracens slaughtered Clermont Auvergne with a 46-6 thrashing at Twickenham to book their place in the Heineken Cup Final.
Saracens boss Mark McCall says Clermont wing Sitiveni Sivivatu is the dangerman in Saturday's Heineken Cup semi-final at HQ.
Clermont centre and skipper Aurélien Rougerie may miss Saturday's huge Heineken Cup semi-final clash with Saracens.
European Cup semi-finalists Clermont host defending Top 14 champions Castres on Friday, hunting a 76th successive home victory.
Leicester Tigers face the seemingly impossible as they head to Clermont for Saturday's enticing Heineken Cup quarter-final.
Clermont will head into next week's Heineken Cup quarter-final with Leicester on the back of a loss after they went down 26-24 at Brive....
Clermont narrowly maintained their winning run at home with a late 22-16 victory over inconsistent title rivals Toulon on Friday.
This weekend's Top 14 action kicks off on Friday with a battle for the championship lead as Toulon face the perilous trip to Clermont....
Clermont's 34-year-old flanker Gerhard Vosloo has signed a contract with Toulon for next season on a potential two-year deal.
The schedule for the Heineken Cup quarter-finals have been confirmed, with three games taking place on Saturday and one on Sunday.
Clermont head coach Vern Cotter has acknowledged how Leicester will be chomping at the bit to make another European final.
France head coach Philippe Saint-André has added flanker Virgile Bruni and full-back Jean-Marcellin Buttin to his Six Nations squad....
Clermont hooker Benjamin Kayser has said that he still has a soft spot for Leicester ahead of their Heineken Cup quarter-final in April....
Brock James landed a crucial late penalty as Clermont battled back to defeat Harlequins 16-13 at The Stoop in Pool 4.