The Scarlets may be out of the Heineken Cup but a victory in France against Castres Olympique could put them in the hunt for the Amlin Challenge Cup quarterfinals.

The Welsh region are only one point behind Northampton Saints in Pool One but can end this weekend on the same number of points if other results go their way in the pool stages.

The Pro12 outfit ran out comfortable 31-23 winners over Castres in Wales in the pool opener but the trip to Stade Pierre Antoine will be anything but easy against a side which beat last season's finalist on their own patch.

The French side's only victory in the tournament, despite an impressive performance away to Munster last weekend, was against the Saints at home and they will be looking to finish a disappointing campaign with a bang.

Castres Olympique: 15 Romain Teulet, 14 Romain Martial, 13 Paul Bonnefond, 12 Pierre-Manuel Garcia, 11 Marc Andreu, 10 Seremaia Bai, 9 Rory Kockott, 8 Chris Masoe, 7 Steve Malonga, 6 Jannie Bornman, 5 Rodrigo Capo Ortega, 4 Scott Murray, 3 Karena Wihongi, 2 Mathieu Bonello, 1 Saimone Taumoepeau.
Replacements: 16 Brice Mach, 17 Yannick Forestier, 18 Michaël Coetzee, 19 Matthias Rolland, 20 Yannick Caballero, 21 Thierry Lacrampe, 22 Pierre Bernard, 23 Max Evans.

Scarlets: 15 Rhys Priestland, 14 George North, 13 Scott Williams, 12 Jon Davies, 11 Liam Williams, 10 Stephen Jones (captain), 9 Rhodri Williams, 8 Matt Gilbert, 7 Johnathan Edwards, 6 Aaron Shingler, 5 Dominic Day 4 Lou Reed, 3 Peter Edwards, 2 Ken Owens, 1 Phil John.
Replacements: 16 Emyr Phillips, 17 Iestyn Thomas, 18 Rhodri Jones, 19 Sione Timani, 20 Richie Pugh, 21 Gareth Davies, 22 Gareth Maule, 23 Viliame Iongi.

Date: Saturday, January 21
Venue: Stade Pierre Antoine, Castres
Kick-off: 19.00 (18.00 GMT)
Referee: JP Doyle