Pool 4: Northampton vs Castres, Saturday 13:00

Saints make three changes for their visit of Castres in the knowledge that they are already eliminated from European competition no matter what happens this weekend. The Pool 4 basement-dwellers rest France No 8 Louis Picamoles with Jamie Gibson given the nod in the back-row, while Harry Mallinder and Juan Pablo Etelles replace JJ Hanrahan and Jamie Elliott respectively.

Castres meanwhile need to beat Northampton as well as Leinster next weekend, both with a bonus point, in order to give themselves a realistic chance of topping the pool.

Pool 2: Wasps vs Toulouse, Saturday 15:15

The standout match of the weekend comes in the standout Pool of the season as Wasps take on Toulouse, with the two sides joined by Connacht at the top of Pool 2 on 13 points with just one team guaranteed progression to the quarter-finals. Joe Launchbury returns to captain the side after recovering from a calf injury but James Haskell is ruled out with concussion, while Joe Simpson is preferred at scrum-half to make his 200th appearance for the club, starting alongside Danny Gopperth.

Four-time winners Toulouse know that a win over Wasps is imperative to their hopes, given the Coventry-based side take on group whipping-boys Zebre next week. The French giants leave former England fly-half Toby Flood on the replacements’ bench with Jean-Marc Doussain preferred at 10, but they do have French internationals Sebastian Bezy, Yoann Huget, Gael Fickou, Maxime Medard and Thierry Dusautoir.

Pool 1: Racing 92 vs Leicester Tigers, Saturday 19:45

Leicester must beat last season’s finalists Racing 92 if they are to stand any chance of qualifying for the last eight, and will have Mathew Tait back at full-back for the Pool 1 encounter at the Stade Yves-Du-Manoir.

Owen Williams, fresh from announcing that he has joined Gloucester from next season, is ruled out with an elbow injury so Freddie Burns switches to fly-half, while Lachlan McCaffrey returns to the back-row to join flankers Mike Williams and William Evans.

Mathew Tait returns from injury to start for Leicester (Getty)

Racing will be guided by two-time World Cup winner Dan Carter at No 10, and have fellow New Zealander’s Joe Rokocoko and Casey Laulala available in a backline that also contains France international Brice Dulin.

Pool 3: Scarlets vs Saracens, Sunday 13:00

Owen Farrell returns after being rested last weekend to take the Saracens captaincy, with Brad Barritt beginning his three-week suspension for a high tackle on Exeter’s Geoff Parling in Saturday’s 13-13 draw. The England fly-half returns to shunt Alex Lozowski to full-back, with Alex Goode is ruled out with an ankle injury, and Chris Ashton returns from a head-knock.

Nick Tompkins starts at centre in place of the suspended Barritt, though Richard Barrington remains in the side despite his red card last weekend for a high shot on Parling in the same tackle, after it was decided he warranted no further action. He’s joined in the front-row by Schalk Brits, in for England hooker Jamie George, and Juan Figallo, while the second and back rows remain unchanged with George Kruis set to miss both this weekend and next week’s crunch clash with Toulon.

Owen Farrell captains Saracens in the absence of Brad Barritt (Getty)

Scarlets will be without Wales centre Jonathan Davies after he was named on the bench, with full-back Liam Williams set to take on the club he will join in the summer. Scarlets are also without international scrum-half Gareth Davies, meaning Aled Davies starts at nine while Samson Lee and Aaron Shingler return to the pack.

Toulon vs Sale, Sunday 15:15

Sale head into the Pool 3 encounter with three-time winners Toulon with mounting problems, as the pointless Sharks face an investigation for a potential breach in their concussion management protocol over TJ Ioane. The 27-year-old Samoan fell to the ground after an attempted tackle on Harlequins’ Dave Ward last weekend, but continued to play the rest of the game and the Concussion management Review Group will now look into the matter.

With their qualification hopes over, director of rugby Steve Diamond makes multiple changes, though retains the same front-row that lost 29-26 to Quins. Jonathan Mills replaces Andrei Ostrikov at lock, while a fresh back-row sees Magnus Lund, David Seymour and Laurence Pearce start. Former Wales scrum-half Mike Phillips with Sam James outside him, while Will Addison skippers the side at outside centre.

Mike Phillips returns to the Sale starting line-up (Getty)

Toulon will need help from the Scarlets if they are to remain in touching distance of pool leaders Saracens, with the two most recent European champions currently separated by eight points ahead of their Allianz Park showdown next week.

Pool 5: Exeter vs Ulster, Sunday 17:30

The final Champions Cup match of the weekend sees Exeter bidding to keep their slim chances of a best runners-up place alive, though even a bonus point victory is unlikely to be enough. They do however welcome Ulster to Sandy Park having rediscovered their form, having lost just once in their last eight matches, and Rob Baxter names a strong side to take on an Ulster side who know defeat will mean they cannot finish top of the pile.

Prop Ben Moon joins locks Mitch Lees and Jonny Hill in returning to the pack, while Dave Lewis replaces injured Will Chudley at scrum-half. Former Ulster centre Ian Whitten starts at 12 alongside Italy international Michele Campagnaro, while James Short is dropped from the wing with Olly Woodburn starting in his place.

Rob Baxter names a strong Exeter line-up to face Ulster (Getty)