Saints have made a handful of tweaks as they look to post a first Heineken Cup win of 2011/12, against Castres at Franklin's Gardens on Sunday.
Northampton come into the meeting having been competitive in the previous three rounds, even if a victory has proved to be frustratingly elusive.
They came home from France last weekend with a try scoring bonus point, but while director of rugby Jim Mallinder says that has been something positive to build on in training this week he has also been putting the team through its paces in a number of other areas.
"We had good attacking intent and scored some good tries last week," he said.
"But we didn't keep hold of the ball well enough and conceded too many penalties. This is something we're going to have to put right this weekend, along with our defence.
"We still want to do as well as we can, and if we can get into the Amlin Challenge Cup then we'll take it without a doubt as it's another opportunity. But to be in with a chance of that we've got to start winning in the Heineken Cup, starting this weekend.
"The players want to prove a point. There are no 'nothing' games at this level and there has been a good response in training this week. You're representing the club every time you pull on the shirt and I expect that the team will come out on Sunday fully motivated for what will be a tough challenge against a Castres outfit that showed their quality last Saturday."
Meanwhile, Castres have chosen not to play Romain Teulet or Chris Masoe in the return fixture at Franklin's Gardens. They are replaced by Florian Denos and Jannie Bornman at full-back and number eight respectively while Max Evans is also not included in the squad.
Rory Kockott, Seremaia Bai and France prop Luc Ducalcon make the replacements bench.
Northampton Saints: 15 Ben Foden, 14 Vas Artemyev, 13 Jon Clarke, 12 James Downey, 11 Jamie Elliott, 10 Steve Myler, 9 Martin Roberts, 8 Samu Manoa, 7 Ben Nutley, 6 Tom Wood, 5 Mark Sorenson, 4 Courtney Lawes, 3 Paul Doran-Jones, 2 Dylan Hartley, 1 Alex Waller.
Replacements: 16 Mikey Haywood, 17 Soane Tonga'uiha, 18 Tom Mercey, 19 James Craig, 20 James Ingle, 21 Lee Dickson, 22 Greig Tonks, 23 Scott Armstrong.
Castres Olympique: 15 Florian Denos, 14 Matthieu Nicolas, 13 Paul Bonnefond, 12 Pierre-Manuel Garcia, 11 Pierre-Gilles Lakafia, 10 Pierre Bernard, 9 Thierry Lacrampe, 8 Jannie Bornman, 7 Steve Malonga, 6 Pierre Roussel, 5 Scott Murray, 4 Matthias Rolland, 3 Rossouw Kruger, 2 Mathieu Bonello, 1 Anton Peikrishvili.
Replacements: 16 Marc-Antoine Rallier, 17 MichaŽl Coetzee, 18 Luc Ducalcon, 19 Rodrigo Capo Ortega, 20 Ibrahim Diarra, 21 Rory Kockott, 22 Seremaia Bai, 23 Vincent Inigo.
Date: Sunday, December 18
Venue: Franklin's Gardens, Northampton
Kick-off: 15.00 GMT
Referee: George Clancy