The competition gets underway with Ireland against Italy at Croke Park, with the 2009 Grand Slam winners hoping to start this year's campaign with a resounding victory.

Ireland
With the in-form fly-half Jonathan Sexton ruled out through injury, Ronan O'Gara regains the number 10 shirt for his 94th international cap. Andrew Trimble comes in on the wing, while lock Leo Cullen was promoted to the starting XV after Donncha O'Callaghan withdrew on Thursday.

Italy
Meanwhile, Italy stick to the same side that achieved a morale-boosting victory against Samoa in November. Fly-half Craig Gower has recovered from a knee injury, with Alessandro Zanni again deputising for injured captain Sergio Parisse in the back row.

Ireland: Kearney, Bowe, O'Driscoll, D'Arcy, Trimble, O'Gara, O'Leary, Healy, Flannery, Hayes, Cullen, O'Connell, McLaughlin, D Wallace, Heaslip.

Replacements: Best, Court, Ryan, O'Brien, Reddan, P Wallace, Earls.

Italy: McLean, Robertson, Canale, Garcia, Mi Bergamasco, Gower, Tebaldi, Perugini, Ghiraldini, Castrogiovanni, Del Fava, Geldenhuys, Sole, Ma Bergamasco, Zanni.

Replacements: Ongaro, Aguero, Bortolami, Derbyshire, Picone, Bocchino, Masi.

Kicking off at 17:00 GMT is England versus Wales at Twickenham.

England
Coach Martin Johnson is confident that his England squad is the best he has ever assembled. However, Ricky Flutey suffered a thigh injury in training, so Toby Flood plays in the unfamiliar role of inside centre. The boot of Jonny Wilkinson will be pivotal to England's chances, while Steve Borthwick retains the captaincy.

Wales
Wales have also been hit by a late blow after Gethin Jenkins failed a late fitness test on Thursday, and his place in the side is taken by Paul James. With Gavin Henson on indefinite leave from the game, James Hook joins Jamie Roberts at centre. Gareth Cooper gets a chance at scrum-half due to injuries to Mike Phillips and Dwayne Peel.

England: D Armitage, Cueto, Tait, Flood, Monye, Wilkinson, Care, Payne, Hartley, Wilson, Shaw, Borthwick, Haskell, Moody, Easter.

Replacements: Thompson, Cole, Deacon, S Armitage, Hodgson, Hape, Foden.

Wales: Byrne, T James, Roberts, Hook, S Williams, S Jones, Cooper, P James, G Williams, A Jones, AW Jones, Charteris, R Jones, M Williams, Powell.

Replacements: Bennett, Gill, Davies, Thomas, R Rees, Bishop, Halfpenny.

Finally, France travel to Scotland on Sunday for a potentially tricky fixture at Murrayfield.

Scotland
Record points scorer Chris Paterson has been restored to the Scotland side for his 99th cap and will fight out kicking duties with fly-half Phil Godman. Paterson will ply his trade at full-back, with Max Evans edging out Alex Grove for a place at centre.

France
French scrum-half Jean-Baptiste Elissalde has been forced to forfeit his place on the substitutes bench after suffering a calf injury in training and has been replaced in the squad by the experienced figure of Frederik Michalak. Indeed, this is the latest of a long line of injury problems for Les Blues, with Fabien Barcella, Sebastien Chabal, Romain Millo-Chluski, Dimitri Yachvili and Damien Traille all unavailable for selection.

Scotland: Paterson, T Evans, M Evans, Morrison, S Lamont, Godman, Cusiter, Dickinson, Ford, Low, Hines, Kellock, Brown, Barclay, Beattie.

Replacements: S Lawson, Jacobsen, R Gray, MacDonald, R Lawson, Grove, Southwell.

France: Poitrenaud, Fall, Bastareaud, Jauzion, Rougerie, Trinh-Duc, Parra, Domingo, Servat, Mas, Nallet, Pape, Dusautoir, Ouedraogo, Harinordoquy.

Replacements: Szarzewski, Ducalcon, Pierre, Bonnaire, Michalak, Marty, Clerc.