Toulouse will look to bounce back from their Heineken Cup upset when they face Perpignan in the Top 14 on Friday.
The four-time European champions have been left licking their wounds after they lost 19-14 to Edinburgh.
However they will be determined for a positive response when they return to domestic action - with the table-toppers set to travel to relegation-threatened Perpignan.
Toulouse should have Luke Burgess, Florian Fritz and Lionel Beauxis in their line-up but Maxime Medard, Gary Botha, Gurthro Steenkamp, Rupeni Caucaunibuca, Romain Millo-Chluski, Akvsenti Giorgadze, Louis Picamoles, Vincent Clerc and Luke McAlister are all ruled out.
Perpignan, who find themselves just six points ahead of 13th-placed Bayonne, will be buoyed by news Damien Chouly has been passed fit to start. The No.8 had initially been doubtful with a thigh injury.
Bayonne face a make or break clash in the Basque derby with Biarritz on Saturday.
Biarritz have put their early season ills behind them to climb eight points clear of the relegation places - with a win over second-placed Clermont last time out highlighting their improvement. However a win for Bayonne could pull them back into the mix.
Bayonne will be without Benjamin Boyet and Marc Baget for the clash, however Sam Gerber, Dwayne Haare and Mark Chisholm are pushing for returns.
Biarritz have injury issues of their own with Marcelo Bosch, Benoit August, Wenceslas Lauret, Takudza Ngwenya, Fabien Barcella and Damien Traille all doubtful.
Bordeaux-Begles will start Saturday seven points clear of trouble, however they face a daunting trip to Castres.
And having lost to bottom club Lyon last time out, Bordeaux are likely to make a number of changes to their line-up - with Thierry Brana, Felix Le Bourhis, Julien Seron, Leroy Houston, Louis-Benoit Madaule, Silviu Florea, Fabien Rofes and Bruce Reihana likely to come into the side.
Michel Denetre and Nicolas Sanchez are definitely ruled out, while Matthew Clarkin broke his nose in the loss to Lyon.
Castres are in danger of slipping out of the play-off picture following their loss to Racing Metro.
And their cause will not be helped by the absence of Mike Coetzee, Brice Mach, Mathias Rolland, Scott Murray and Paul Bnnerfond. Kulemine Kirill is set to return, though.
Racing Metro are now just one point off a top-six place and they will entertain Brive full of confidence.
The Parisians will be strengthened further by the returns of Andrea Lo Cicero, Remy Bianchin, Bernard Le Roux and Guillaume Bousses.
Brive, though, will be no pushovers and they showed how dangerous they can be with a crucial 14-9 win over Toulon followed by their Amlin Challenge Cup success over the Scarlets.
England back Shane Geraghty and Argentinean prop Pablo Henn are both doubtful for the clash, though.
Heineken Cup semi-finalists Clermont are counting the cost of their win over Saracens with a number of players set to miss the visit of Stade Francais.
Wesley Fofana, Nathan Hines, Jamie Cudmore and Adrien Oleon will all miss out through injury, while Morgan Parra is rested.
However Clermont should welcome back Loic Jacquet, Alexandre Audebert and Noa Nakaitaci.
Pascal Pape and Julien Dupuy will return to the Stade line-up, however Dimitri Szarzewski and David Attoub are set to miss out.
Toulon will look to build on their Amlin Challenge Cup success over Harlequins when they travel to Agen.
Sebastien Bruno, Christophe Samson, Sebastien Tillous-Borde and Jonny Wilkinson have been rested for the trip, however Matt Henjak and Juan Martin Fernandez Lobbe are set to return.
Agen, themselves, will be missing Lisiate Fa'aoso, Ueleni Fono, Opeti Fonua and Arsene N'nomo. However Gert Muller, Brice Dulin, Julien Janaudy, Antoine Erbani and Thibault Lassalle are pushing for recalls.
Montpellier will be without Benoit Paillaugue, Yoan Audrin, Naama Leleimalefaga, Ali Fakate and Drickus Hancke for the visit of Lyon.
Montpellier, who are currently in fourth, will welcome back Mickael De Marco, Benjamin Thiery and Seta Tuilevuka, though.
Lyon's resources have been stretched, with Romain Loursac and Antoine Guillamon having picked up injuries in the win over Bordeaux.
The victory gave Lyon hope of pulling off the great escape, although they remain 10 points adrift at the bottom.