One of the stand-out games of the Heineken Cup weekend comes from the Stoop where Harlequins entertain Clermont in a tasty Pool 4 meeting
The reverse fixture between these two teams saw Les Jaunards win 23-16 and they've subsequently gone on to be four points clear before kick-off.
Despite their power and also the fact they sit atop the Top 14, Clermont are not in great health coming into this clash as they will enter the Stoop without Regan King, Damien Chouly, Julien Bonnaire and Thierry Lacrampe. One boost is the surprise comeback from injury of Morgan Parra.
Parra's swift return to match fitness cannot be downplayed as at scrum-half he is the general of this Clermont team. Put simply, he makes them tick, with the battle against Danny Care just one of many subplots to watch. Matt Hopper, snubbed by England, versus AurÃ©lien Rougerie being another.
Hopper's absence from any of the Elite Player Squads came as a huge surprise, particularly as England don't have anyone who's regulary playing thirteen on club duty in their group for the Six Nations. Again, there's set to be someone out of position on the international stage.
Blonde duo Hopper and Charlie Walker have been excellent this year and should be closely monitored by Clermont as they have done damage in the wide channels against all they've faced. The experienced balance of Mike Brown and Nick Evans has aided their progress.
Team news sees Nick Kennedy make his starting debut and partners George Robson in the second-row. Ugo Monye and Care return, while Luke Wallace is named at blindside.
Among the replacements, Joe Gray returns from injury to provide cover for Dave Ward, while scrum-half Karl Dickson will look to make his 100th appearance for the Premiership club.
Clermont meanwhile name a fearsome looking backline as the likes of Sitiveni Sivivatu, Rougerie, Wesley Fofana and Napolioni Nalaga start outside Parra and Brock James.
The in-form Fritz Lee is named at number eight alongside Alexandre Lapandry and Julien Bardy while Nathan Hines and Jamie Cudmore form a physical lock combination.
Harlequins: 15 Mike Brown, 14 Charlie Walker, 13 Matt Hopper, 12 Tim Molenaar, 11 Ugo Monye, 10 Nick Evans, 9 Danny Care, 8 Nick Easter, 7 Chris Robshaw (capt), 6 Luke Wallace, 5 George Robson, 4 Nick Kennedy, 3 Will Collier, 2 Dave Ward, 1 Joe Marler.
Replacements: 16 Joe Gray, 17 Mark Lambert, 18 Paul Doran-Jones, 19 Charlie Matthews, 20 Tom Guest, 21 Karl Dickson, 22 Ben Botica, 23 Ollie Lindsay-Hague.
Clermont: 15 Jean-Marcel Buttin, 14 Sitiveni Sivivatu, 13 AurÃ©lien Rougerie (capt), 12 Wesley Fofana, 11 Napolioni Nalaga, 10 Brock James, 9 Morgan Parra, 8 Fritz Lee, 7 Alexandre Lapandry, 6 Julien Bardy, 5 Nathan Hines, 4 Jamie Cudmore, 3 Davit Zirakashvili, 2 Benjamin Kayser, 1 Thomas Domingo.
Replacements: 16 Ti'i Paulo, 17 Vincent Debaty, 18 ClÃ©ment Ric, 19 Julien Pierre, 20 Gerhard Vosloo, 21 Ludovic Radoslavjevic, 22 Mike Delany, 23 Benson Stanley.
Date: Saturday, January 12
Kick-off: 13:35 GMT
Venue: Twickenham Stoop
Referee: John Lacey (Ireland)
Assistant referees: Gary Conway (Ireland) Brian MacNiece (Ireland)
Television match official: Simon McDowell (Ireland)