Last eight welcome back their Six Nations contingents

Nicolas Mas, Guilhem Guirado et Henry Tuilagi all return for Perpignan for their trip to the French coast to play Amlin Challenge Cup quarter-finalists La Rochelle.

Mas and Guirado return from international duty and are named in a provisional 27-man squad for the game.

Castres v Toulon

Toulon have also announced a 27-man squad for their game against third placed Castres this evening.

Gavin Henson is included in the squad for the first time since making the move across the channel, while Rory Lamont and Jonny Wilkinson return from Six Nations duty to take their place in squad.

Newport Gwent Dragons v Leinster

Leinster are boosted by the return of their international contingent for the trip to South Wales as well as the return of Shane Horgan who lines up for the first time in two months after injury.

Ireland stars Jonathan Sexton and Leo Cullen both start while Jamie Heaslip, Nathan Hines and Eoin Reddan are named amongst a replacements bench.

Bath v Leicester Tigers

English Premiership leaders, Leicester Tigers welcome back Six Nations champions Toby Flood, Ben Youngs, Dan Cole and Tom Croft for their clash against Bath this weekend.

They are without Louis Deacon, Martin Castrogiovanni and George Skivington who are all injured but Marcos Ayerza and Alesana Tuilagi make their 100th starting appearances for the club.

Northampton Saints v London Wasps

Northampton host Amlin Challenge Cup quarter-finalists London Wasps at Franklin's Gardens and are boosted by the return of Ben Foden, Chris Ashton and Tom Wood.

Scotland's Joe Ansbro is ruled out with injury but it is hoped he will be back in time for the Saints' Heineken Cup clash against Ulster in just over a fortnights time.

Glasgow Warriors v Ulster

Ulster welcome back international trio Tom Court, Paddy Wallace and Simon Danielli to the starting team for their trip to Glasgow this evening.

Rory Best takes a place amongst the replacements for Ulster, who are currently fourth in the Magners League. Andrew Trimble, who played on the wing for Ireland last weekend, picked up a slight quad injury and misses the game.

Biarritz Olympique v Bayonne

Biarritz Olympique host Bayonne in the Basque derby this weekend and the game has extra spice with just three points separating the teams in the table.

Prop Sylvain Marconnet and lock Jérôme Thion are expected to start after not featuring for France in their final Six Nations game.

Racing Metro v Toulouse

Lenient Poitrenaud and Yannick Jauzion are likely to start for European Champions Toulouse in the top of the table clash against Racing Metro after not taking part in France's last Six Nations game against Wales at the weekend.

Vincent Clerc, Mazime Médard, Thierry Dusautoir and Williams Servat were all given extra time off this week following their International duties and are likely not to feature in the Top 14 this week.

Teams:

Perpignan Team: Mas, Pulu, Brison, Freshwater, Schuster, Guirado, Geli, Tchale-Watchou, Alvarez-Kairélis, Taofifenua, Bézian, Tuilagi, Chouly, Guiry, Arnaudies, Mélé, Cazenave, Boulogne, Laharrague, Edmonds, Coetzee, Michel, Sid, Candelon, Planté, Batlle, Porical

Toulon Team: Benjamin BASTERES, Kris CHESNEY, Joe EL ABD, Laurent EMMANUELLI, Juan Martin FERNANDEZ LOBBE, Carl HAYMAN, Mickaël IVALDI, Davit KUBRIASHVILI, Olivier MISSOUP, Jean-Charles ORIOLI, Christophe SAMSON, Dean SCHOFIELD, George SMITH, Saimone TAUMOEPEAU, Joe VAN NIEKERK (Cap.), Fabien CIBRAY, Felipe CONTEPOMI, Gavin HENSON, Rory LAMONT, Benjamin LAPEYRE, Christian LOAMANU, Gabiriele LOVOBALAVU, Geoffroy MESSINA, Pierre MIGNONI, Paul SACKEY, Jonny WILKINSON, Rudi WULF.

Leinster Team: Isa Nacewa, Shane Horgan, Eoin O'Malley, Fergus McFadden, Luke Fitzgerald, Jonathan Sexton, Isaac Boss, Heinke van der Merwe, Richardt Strauss, Stan Wright, Leo Cullen (Capt), Devin Toner, Kevin McLaughlin, Dominic Ryan, Rhys Ruddock Replacements: Aaron Dundon, Jack McGrath, Simon Shawe, Nathan Hines, Jamie Heaslip, Eoin Reddan, Ian Madigan, Dave Kearney.

Leicester Team: Scott Hamilton, Horacio Agulla, Manu Tuilagi, Anthony Allen, Alesana Tuilagi, Toby Flood, Ben Youngs, Marcos Ayerza, George Chuter, Dan Cole, Steve Mafi, Ed Slater, Tom Croft, Craig Newby (c), Thomas Waldrom
Replacements: Rob Hawkins, Boris Stankovich, Julian White, Jordan Crane, Ben Woods, James Grindal, Jeremy Staunton, Matt Smith

Northampton Saints Team: Ben Foden, Chris Ashton, Jon Clarke, James Downey, Paul Diggin, Stephen Myler, Lee Dickson, Soane Tonga'uiha, Dylan Hartley (capt), Brian Mujati, Courtney Lawes, Christian Day, Phil Dowson, Tom Wood, Roger Wilson. Replacements: Brett Sharman, Alex Waller, Tom Mercey, Mark Sorenson, Calum Clark, Stuart Commins, Shane Geraghty, Bruce Reihana

Ulster Team: S Danielli; C Gaston, N Spence, P Wallace, C Gilroy; R Pienaar, P Marshall; Tom Court, A Kyriacou, D Fitzpatrick, J Muller (capt), D Tuohy, R Diack, C Henry, P Wannenburg;
Replacements: R Best, P McAllister, B Young, T Barker, W Faloon, I Whitten, T Seymour, A D'Arcy.

Biarritz Olympique Team: TBC

Toulouse Team: TBC