Exeter Chiefs head coach Rob Baxter has made six changes to his starting XV from that of a week ago as he looks to shock Toulon at Stade Félix Mayol.
Two of the alterations see James Hanks and Don Armand come in for Damian Welch and Ben White; whilst behind Haydn Thomas and Henry Slade are the new half-back duo, Tom James starts at wing ahead of Matt Jess and Ian Whitten is preferred to Jason Shoemark in the centre.
It means first European starts for Armand, James and Slade, the latter of whom replaces the injured Gareth Steenson. The Irishman has failed to recover fully from a heavy Mathieu Bastareaud hit sustained last weekend, so Slade is elevated from the bench and his place on the sidelines is filled by Ceri Sweeney, who is joined by Will Chudley and Sam Hill in the other changes.
Baxter knows a win is vital for his side's long-term prospects in the competition and hopes the near travelling Chiefs fans will play their part.
"What you have to do is try and keep everything in your hands for as long as possible," explained Baxter.
"The reality for us is that if we lose again qualification slips out of our hands, so I think we have to keep things exciting and in our hands for as long as possible. We maybe let an opportunity slip here last week, but if we get an opportunity this week we can't afford to let it slip this time.
"Having the backing of our fans over there will be fantastic. It's brilliant when your hear the Tomahawk Chop in the stands because sometime you wonder just how they make so much noise.
"At the same time, though, this is kind of what the whole journey has been about for us. It's gradually moving forward and achieving new things for not only our players, but also our supporters to experience. This is what it is all about and I'm delighted we have so many fans going over. We have worked hard for this to happen and when opportunities like this come along, you kind of have to make the most of them."
Meanwhile, Toulon have made several changes to their line-up for this reverse fixture.
Bryan Habana and Bakkies Botha aren't involved in the matchday 23 while Jonny Wilkinson is on the rplacements bench as Matt Giteau moves into the number 10 jersey this week.
Carl Hayman comes in at tighthead prop instead of Martin Castrogiovanni while Jean-Charles Orioli replaces the injured Craig Burden, who suffered a torn bicep last weekend.
Toulon: 15 Drew Mitchell, 14 Alexis Palisson, 13 Mathieu Bastareaud, 12 Maxime Mermoz, 11 David Smith, 10 Matt Giteau, 9 Sébastien Tillous-Borde, 8 Chris Masoe, 7 Steffon Armitage, 6 Juan Smith, 5 Ali Williams, 4 Jocelino Suta, 3 Carl Hayman, 2 Jean-Charles Orioli, 1 Florian Fresia.
Replacements: 16 Benjamin Noirot, 17 Xavier Chiocci, 18 Martin Castrogiovanni, 19 Virgile Bruni, 20 Delon Armitage, 21 Jonny Wilkinson, 22 Frédéric Michalak, 23 Konstantin Mikautadze.
Exeter Chiefs: 15 Luke Arscott, 14 Jack Nowell, 13 Ian Whitten, 12 Phil Dollman, 11 Tom James, 10 Henry Slade, 9 Haydn Thomas, 8 Dave Ewers, 7 Don Armand, 6 Tom Johnson, 5 James Hanks, 4 Dean Mumm (capt), 3 Hoani Tui, 2 Jack Yeandle, 1 Ben Moon.
Replacements: 16 Chris Whitehead, 17 Brett Sturgess, 18 Alex Brown, 19 Damian Welch, 20 Ben White, 21 Will Chudley, 22 Ceri Sweeney, 23 Sam Hill.
Date: Saturday, 14 December
Venue: Stade Felix Mayol
Kick-off: 14:35 local, 13:35 GMT
Referee: John Lacey (Ireland)
Assistant referees: David Wilkinson, Michael Black (both Ireland)
TMO: Dermot Moloney (Ireland)