NatWest 6 Nations rivalries resume in European quarter-finals.

The 2018 NatWest 6 Nations is only two weeks old and already the return of European rugby has thrown up some mouth-watering re-matches.

The 2018 NatWest 6 Nations is only two weeks old and already the return of European rugby has thrown up some mouth-watering re-matches.

This week’s Champions Cup and Challenge Cup quarter-finals bring together the great and the good of the world game and there are Championship scores to settle.

Click here for the final 2018 NatWest 6 Nations standings

Not least on Sunday at the Aviva Stadium where the fourth and final Champions Cup quarter-final sees Saracens take on Leinster.

No fewer than 19 players involved in Ireland’s Grand Slam decider with England earlier this month will be in action and there are compelling head to head clashes to look out for.

In particular the battle at No.10 where Owen Farrell has recovered from his thigh injury to start at fly-half against Jonathan Sexton who was rested last week in preparation for this titanic clash.

The two playmakers for The British & Irish Lions last summer, Farrell and Sexton will be absolutely vital to the outcome on Sunday in Dublin.

But elsewhere, the second row sees Maro Itoje and the returning George Kruis take on Grand Slammers James Ryan and Devin Toner.

In the front row Jamie George and Mako Vunipola pack down for Sarries while Cian Healy, Tadhg Furlong and Sean Cronin are all back in action for Leinster.

Leinster also have Garry Ringrose back at 13, Isa Nacewa skippers the side from 12, while Dan Leavy and Jordi Murphy join Scott Fardy in the back row.

Sarries welcome Richard Wigglesworth back to partner Farrell while Liam Williams and Sean Maitland who both caught the eye for Wales and Scotland respectively in the Championship are in action on the wings.

The Champions Cup gets underway on Friday when Scarlets host La Rochelle, and the Welsh region are looking to make the semi-finals for the first time in over a decade.

The likes of Leigh Halfpenny, Hadleigh Parkes and Gareth Davies return from strong Wales outings in the last two months while up front expect sparks to fly as Rob Evans and Ken Owens pack down in the front row against a La Rochelle front row that includes France debutant this Championship Dany Priso.

Scotland skipper John Barclay is also back in a Scarlets pack that includes Aaron Shingler, James Davies and Samson Lee.

On Saturday Munster – with their Grand Slam trio of Peter O’Mahony, Conor Murray and CJ Stander back in the starting XV – welcome Toulon to Thomond Park.

Simon Zebo and Andrew Conway have also both been passed fit to return to take on a Toulon side that includes three key Frenchman from this year’s NatWest 6 Nations.

Skipper Guilhem Guirado is fit to return, as is his lieutenant Mathieu Bastareaud while Francois Trinh-Duc starts at No.10.

The other quarter-final sees Clermont – with Camille Lopez and Wesley Fofana on the bench but Morgan Parra, Remy Grosso and Rabah Slimani in the starting XV – take on Top 14 rivals Racing 92.

Racing have Teddy Thomas back in action and his head to head with Grosso should make for fascinating viewing for Jacques Brunel as France prepare for a summer tour of New Zealand.

Parra meanwhile, who missed the Championship with injury, takes on the man who took on the No.9 jersey and thrived this spring in Maxime Machenaud.

Meanwhile, in the Challenge Cup Connacht welcome Gloucester on Saturday with Bundee Aki back at outside centre and Kieran Marmion at scrum-half after their Grand Slam efforts with Ireland.

Gloucester have Ross Moriarty at blindside flanker and Owen Williams at fly-half while Toby Flood and Chris Harris are in action for Newcastle when they take on Brive.

And finally, Sergio Parisse and Paul Gabrillagues are on the bench for Stade Français against Pau and Blair Kinghorn and Gareth Anscombe face off at full-back as Edinburgh welcome Cardiff Blues to the Scottish capital.