Ulster play Edinburgh this evening in Murrayfield and coach Mark McCall has named a strong side which includes David Humphreys, Simon and Rory Best and Andrew Trimble.
Leinster travel to Wales to play Newport Gwent Dragons. Michael Chieka has named Girvan Dempsey, Denis Hickie and Rob Kearney in a strong back three for the trip.
Munster play host to Glasgow in Thomond park on Saturday and Declan Kidney has made three changes to the side which beat Dragons in the last Celtic League game. John Kelly comes in for Ian Dowling, Trevor Halsted for Gary Connolly and Donncha O'Callaghan for Trevor Hogan.
Connacht coach Michael Bradley has named a 26 man squad for theis game against Scarlets at 14:30 on Saturday in The Sportsground.
...Bryn Cunningham of Ulster in action...
Ulster: 15 Bryn Cunningham, 14 James Topping, 13 Andrew Trimble, 12 Paul Steinmetz, 11 Andrew Maxwell, 10 David Humphreys, 9 Isaac Boss, 8 Roger Wilson, 7 Stephen Ferris, 6 Neil Best, 5 Matt McCullough, 4 Justin Harrison, 3 Simon Best (captain), 2 Rory Best, 1 Bryan Young.
Replacements: 16 Nigel Brady, 17 Justin Fitzpatrick, 18 Rowan Frost, 19 Neil McMillan, 20 Kieran Campbell, 21 Adam Larkin, 22 Jonathan Bell.
...John Hearty of Connacht named in 26 man squad...
Connacht Forwards: Ray Hogan, Stephen Knoop, Dan McFarland, Adrian Clarke, John Fogarty, Joe Merrigan, David Gannon, Christian Short, Andrew Farley, Michael Swift, Matt Lacey, John Muldoon, Colm Rigney, Brendan O'Connor.
Backs: Tom Tierney, Chris Keane, David Slemen, Paul Warwick, Conor McPhillips, Darren Yapp, Andrew Mailei, Keith Matthews, Gavin Williams, John Hearty, Matt Mostyn, Mark McHugh.
...Girvan Dempsey scores for Leinster...
Leinster: 15 Girvan Dempsey, 14 Rob Kearney, 13 Kieran Lewis, 12 John Hepworth, 11 Denis Hickie, 10 Felipe Contepomi (captain), 9 Guy Easterby, 8 Jamie Heaslip, 7 Keith Gleeson, 6 Eric Miller, 5 Bryce Williams, 4 Adam Byrnes, 3 Will Green, 2 Brian Blaney, 1 Reggie Corrigan
Replacements: 16 David Blaney, 17 Ronan McCormack,18 Ben Gissing, 19 Niall Ronan, 20 Brian O'Riordan, 21 Eoghan Hickey, 22 Gary Brown
...Barry Murphy supported by Ronan O'Gara...
Munster: 15 S Payne; 14 J Kelly; 13 B Murphy; 12 T Halstead; 11 A Horgan; 10 M Lawlor; 9 T O'Leary; 1 F Roche; 2 D Fogarty; 3 F Puciariello; 4 D O'Callaghan; 5 M O'Driscoll; 6 S Keogh; 7 J O'Connor; 8 A Foley capt. Replacements: T Buckley, M Horan/E McGovern, T Hogan, J O'Sullivan, M Prendergast, B Keeshan, G Connolly