The Champions Cup is set for another enthralling weekend of action as the return legs of the double headers are played and pools continue to take shape.
ESPN brings you the latest team news ahead of round four.
FRIDAY
Kingspan Stadium, 7.45 p.m.
Ulster have made just two changes to their starting XV as they welcome Harlequins to the Kingspan Friday night. Chris Henry, who impressed off the bench in the victory over Harlequins last time out, has earned a start in the hosts' back row. Tommy Bowe misses out through injury, meanwhile, meaning Louis Ludik will start.
Harlequins director of rugby John Kingston has made six changes to his side that lost to Ulster in the snow last Sunday. Lewis Boyce comes into the front row in place of the injured Joe Marler, while Dave Ward -- who captains the team -- and Archie White are selected in the back row as Chris Robshaw and Danny Care both miss out with concussion. Care's absence means Ian Prior starts at scrum-half, while Winston Stanley comes into the midfield alongside Jamie Roberts, Ross Chisholm starts at fullback and Alofa Alofa moves to the left wing.
SATURDAY
Stadio Comunale di Monigo, 1 p.m.
Treviso make eight changes to the side that came agonisingly close to beating Scarlets last week. Up front only Tizano Pasquali and Sebastian Negri remain, while Tito Tebaldi at scrum-half and Luca Morisi are the only changes to the backline.
Scarlets coach Wayne Pivac has made four changes to his Scarlets side as they look to secure a second successive victory over the Italians. Wales fly-half Rhys Patchell is ruled out with concussion but Pivac is able to welcome back Scott Williams, Dan Jones, Rob Evans and Will Boyde.
Altrad Stadium, 1 p.m.
Vern Cotter has made four changes to his Montpellier starting XV as he welcomes some familiar faces to the south of France. Gabriel Ngandebe replaces Benjamin Fall on the right wing, while Benoit Paillague returns to partner Aaron Cruden at half-back. Up front, Gregory Fichten starts in the front row alongside incoming hooker Romain Ruffenach.
Glasgow coach Dave Rennie has remained true to his word and making six personnel and one positional change to his side for the trip to France. Lee Jones returns to the left wing, meaning Tommy Seymour switches across to the opposite flank, while Nick Grigg and Alex Dunbar start in the centres and Peter Horne starts at fly-half in place of Finn Russell. Fraser Brown is handed a start at hooker while Kiran McDonald comes into the second row.
Aviva Stadium, 3.15 p.m.
Leinster boss Leo Cullen has made one personnel and one positional change to his Leinster starting XV as they prepare to face Chiefs in front of a 40,000-strong crowd at the Aviva Stadium. Rhys Ruddock misses out with a hamstring injury, meaning Josh van der Flier comes into the back row with Sean O'Brien swapping the No. 7 shirt for No. 6.
Jack Nowell returns to the Chiefs starting XV following injury, having been a replacement at Sandy Park last weekend. Nowell's England teammate Sam Simmonds is also recalled by Rob Baxter in place of Thomas Waldrom. Meanwhile, Phil Dollman's injury means that Lachie Turner is handed the No. 15 jersey, while there are also starts for Tomas Francis and Ben Moon in the front row, and Sam Skinner at lock.
Stade Yves du Manoir, 3.15 p.m.
Racing go into their must win game against Castres with six new faces in the starting lineup. While Juan Imhoff moving from the wing to fullback, Virimi Vakatawa and Louis Dupichot start on the wing, with Anthony Tuitavake at centre. Up front Bernard Le Roux, Donnacha Ryan and Cedate Gomes Sa complete the changes.
Castres ring the changes for their trip to Top 14 rivals Racing 92 as head coach Christophe Urios makes 11 alterations to the team which won 16-13 last time out. Yannick Caballero is the only forward to keep his place as Steve Mafi and Loic Jacquet return, while Rory Kockott's inclusion at scrum-half is the key change to the backs.
The Rec, 5.30 p.m.
Matt Banahan will make his 250th Bath appearance on the left wing against Toulon, as Todd Blackadder makes two changes to the side that lost narrowly in France last weekend. Taulupe Faletau's knee injury allows Francois Louw to reclaim his place in the back row with Paul Grant shifting across to No. 8. The only other change sees Charlie Ewels come in for Luke Charteris in the second row.
Toulon may be top of the pile in Pool 5, but defeat against Toulon could see them slip to second, and should Scarlets gain a bonus-point win at Treviso, they could drop to third in defeat. Chris Ashton's blushes were spared last week and reverts to his favoured position on the left wing with Hugo Bonneval at fullback. Guilhem Guirado and Marcel Van Der Merwe return in the front row and Argentine Facundo Isa starts in the backrow.
SUNDAY
Ricoh Arena, 1 p.m.
Nathan Hughes will make his first appearance since picking up an injury on England duty last month, as he returns to the Wasps side to face La Rochelle Sunday. Fullback Willie Le Roux is also back in Dai Young's side after he recovered from the illness that kept him out last weekend.
Having scored six tries against Wasps last week, La Rochelle make eight changes, with the biggest talking point being Rene Ranger's first start for the TOP 14 side. Gabriel Lacroix, Paul Jordan and Ryan Lamb also come into the backline. Up front Hikairo Forbes has been promoted to from the bench, Jason Eaton starts in the second row with Afa Amosa and Kevin Gourdon both drafted into the backrow.
Liberty Stadium, 3.15 p.m.
Wales flanker Justin Tipuric returns to the Ospreys back row as the PRO14 side makes two personnel and one positional change for the visit of Northampton. With Tipuric back at openside flanker, Olly Cracknell moves to No. 8 while Ben John is included on the right wing in place of Henno Dirksen, who received a red card in the closing stages at Franklin's Gardens.
The first Saints team since the departure of Jim Mallinder as director shows four changes, with Dylan Hartley, Courtney Lawes, Christian Day, Lewis Ludlam and Luther Burrell all making way. Mike Haywood, Michael Paterson, Jamie Gibson, Tom Wood and Tom Stephenson all come in.
Stade Marcel-Michelin, 3.15 p.m.
How to improve on perfection is Franck Azema's task this week but injury has forced him into two changes in the pack. Sitaleki Timani misses out with concussion while Judicael Cancoriet won't be risked having twisted his ankle last week. In what is arguably a stronger selection, Flip Van der Merwe comes into the second row, with Peceli Yato at No. 6.
Richard Wigglesworth, Brad Barritt and Schalk Burger have paid the price after Saracens' collapse last Monday. In comes Ben Spencer at scrum-half, Alex Lozowski at centre and Nick Isiekwe to the backrow as Mark McCall side's chances of progressing to the knockout stages hang in the balance.
Welford Road, 5.30 p.m.
Leicester hope to avenge the 33-10 defeat they suffered at Thomond Park a week ago with Matt O'Connor bringing in Mike Williams for Luke Hamilton in the backrow. The Aviva Premiership side are given a boost in the backs, with Matt Toomua and Manu Tuilagi both returning from injuries to resume their partnership at centre. Elsewhere Matthew Tait drops to fullback for the injured Telusa Veainu.
Munster head coach Johann van Graan meanwhile has made just two changes to the team that tamed the Tigers last weekend. While Andrew Conway and Rhys Marshall are still undergoing return to play protocols, hooker Kevin O'Byrne and winger Darren Sweetnam are promoted from the bench. Keith Earls and Niall Scannell have recovered from injuries to feature among the replacements for the PRO14 outfit.