Pool One
Wasps are without the injured back-rows Nathan Hughes and Brad Shields for their must-win encounter with pool leaders Toulouse. As a result, Ben Morris makes his European debut at blindside flanker while Billy Searle comes in a fly-half for Dai Young’s side. For Toulouse, Romain Ntamack starts at inside-centre. Bath, who, who like Wasps, must win their return fixture against Leinster to have any realistic chance of reaching the quarter-finals, are without the injured Joe Cokanasiga so Cooper Vuna comes in. Johnny Sexton is named as Leinster’s captain despite concerns over a calf injury.
Toulouse v Wasps Saturday 3.15pm
Leinster v Bath Saturday 5.30pm
Pool Two
Joey Carbery has been named to start for Munster at fly-half in their only change for the second part of their double-header against Castres. Carbery was named in the starting lineup for last weekend’s victory but pulled out with a hamstring injury and was replaced by JJ Hanrahan, who scored 20 points in the 30-5 home win. Munster begin round four top of the pool and victory against the Top 14 champions will take them a significant step closer to qualification. Castres make seven changes, introducing a new front row, while Rory Kockott comes in at scrum-half.
Castres v Munster Saturday 5.30pm
Pool Three
Saracens welcome back George Kruis for his first appearance since suffering a calf injury during England’s autumn campaign for their trip to Cardiff. Kruis lines up alongside Will Skelton in the second row while Ben Earl is rewarded for his impressive showing from the bench last week with a start at No 8. Cardiff are boosted by the returns of the centres Willis Halaholo and Rey Lee-Lo as well as the openside flanker Josh Navidi. Glasgow, who can boost their chances of reaching the knockout with another victory over Lyon, make eight changes with Stafford McDowall making his first European start at inside-centre.
Cardiff v Saracens Saturday 1pm Glasgow v Lyon Saturday 1pm
Pool Four
Leicester make only one change to the side that lost an entertaining match at Racing 92 last weekend with Graham Kitchener coming back in, meaning Ben White continues at scrum-half in place of Ben Youngs. Gareth Owen returns to the bench for the Tigers, in place of the injured Matt Smith, who suffered a dislocated shoulder in Paris. Facundo Gigena is also among the replacements in place of Campese Ma’afu. Maxime Machenaud is on the bench for last season’s runners-up, seven months after suffering a torn ACL.
Leicester v Racing Sunday 1pm
Pool Five
Newcastle ring the changes for their home fixture against Edinburgh with Mark Wilson recovering from an ear infection to take his place in the back row. Sinoti Sinoti and Niki Goneva are on the wings while Toby Flood captains the side from fly-half. Dean Richards’s problems at tighthead have also eased with Trevor Davison fit to start while Jack Payne has now been registered and takes his place on the bench as cover. Edinburgh make two changes with Allan Dell and Luke Hamilton selected. Toulon call on François Trinh-Duc, Guilhem Guirado and Mathieu Bastareaud for their trip to Montpellier, who welcome back Louis Picamoles.
Montpellier v Toulon Sunday 3.15pm
Newcastle v Edinburgh Sunday 3.15pm