Munster will look to maintain their impressive unbeaten record in Heineken Cup Pool 1 this season against Castres in Limerick on Saturday.
Munster needed a drop-goal from Ronan O'Gara at the death to edge past Castres in the away leg.
Another victory would almost certainly guarantee the two-time champions a place in the knock-out stages before having to go to Milton Keynes to face Northampton next weekend.
If Munster win and Scarlets lose, or if Scarlets win without the bonus, then the Irish Province are through to the quarter finals.
Castres, who have nothing to play for but pride, have only managed one win during this campaign and face a daunting prospect against a side that has won their last 16 Heineken Cup games at Thomond Park.
Munster coach Tony McGahan has retained the same team that delivered the bonus-point over Treviso win last weekend.
The one area that would have caused McGahan to ponder would have been the second row and whether to start Donnacha Ryan or Donncha O'Callaghan, who made such an impression when he came on as a first half replacement against Treviso, but Ryan gets the nod to partner skipper Paul O'Connell.
For Castres, sharp-shooter Pierre Bernard starts at fly-half while young Romain Martial is at full-back.
Former Sharks and Lions scrum-half Rory Kockott is on the bench along with Fijian playmaker Seremaia Bai.
Munster:15 Denis Hurley, 14 Johne Murphy, 13 Keith Earls, 12 Lifeimi Mafi, 11 Simon Zebo, 10 Ronan O'Gara, 9 Conor Murray, 8 James Coughlan, 7 Niall Ronan, 6 Peter O'Mahony, 5 Paul O'Connell (c), 4 Donnacha Ryan, 3 BJ Botha, 2 Damien Varley, 1 Wian du Preez.
Replacements: 16 Denis Fogarty, 17 Marcus Horan, 18 Stephen Archer, 19 Donncha O'Callaghan, 20 Billy Holland, 21 Tomas O'Leary, 22 Ian Keatley, 23 Danny Barnes.
Castres Olympique: 15 Romain Martial, 14 Vincent Inigo, 13 Paul Bonnefond, 12 Pierre-Manuel Garcia, 11 Pierre-Gilles Lakafia, 10 Pierre Bernard, 9 Thierry Lacrampe, 8 Jannie Bornman, 7 Steve Malonga, 6 Yannick Caballero, 5 Rodrigo Capo Ortega, 4 Matthias Rolland, 3 Anton Peikrishvili, 2 Marc-Antoine Rallier, 1 Saimone Taumoepeau.
Replacements: 16 Mathieu Bonello, 17 Michaël Coetzee, 18 Karena Wihongi, 19 Scott Murray, 20 Ibrahim Diarra, 21 Rory Kockott, 22 Seremaia Bai, 23 Matthieu Nicolas.
Date: Saturday, January 14
Venue:Thomond Park, Limerick
Kick-off: 15.40 GMT
Referee: Andrew Small