Top 14 leaders Clermont have been hit by a string of injuries ahead of their trip to Castres this weekend with centre Aurelien Rougerie and wing Napolioni Nalaga sidelined, the club confirmed. Captain Rougerie is still suffering from a back injury he picked up during a 44-20 win over Grenoble two weeks ago, while Nalaga is rested after receiving a knock to his ribs during Friday\'s 28-25 victory over Stade Francais. Prop Vincent Debaty (leg) and lock Jamie Cudmore (thigh) are also doubtful. But South African flanker Gerhard Vosloo, who has been out since last April after a groin operation, is expected to return. Scrum-half Morgan Parra will also be missing because he has holidays to take after playing 505 of the 560 minutes played by the team since the beginning of the season.