Leinster coach Matt O’Connor has made just one change for their sold-out clash with Castres at the RDS (Saturday 3.40pm) with prop Martin Moore replacing the injured Mike Ross.

Ireland front rower Ross has failed to fully recover from a hamstring injury that saw him replaced by Martin in last week’s win over Opsreys.

Out-half Jimmy Gopperth retains the number 10 jersey ahead of Ian Madigan, while Brian O'Driscoll has not recovered from a calf strain. 

Leinster: Rob Kearney, Fergus McFadden, Brendan Macken, Gordon D'Arcy, Dave Kearney, Jimmy Gopperth, Isaac Boss; Cian Healy, Sean Cronin, Martin Moore, Devin Toner, Mike McCarthy, Kevin McLaughlin, Sean O'Brien, Jamie Heaslip (c).

Replacements: Aaron Dundon, Jack McGrath, Michael Bent, Quinn Roux, Rhys Ruddock, Eoin Reddan, Ian Madigan, Luke Fitzgerald.

Captain Peter O’Mahony returns to the Munster starting XV for their Pool 6 tie with Gloucester at Thomond Park (Saturday 6pm).

O’Mahony missed the defeat to Edinburgh last weekend but comes in at number 8 in place of James Coughlan.

It is one of a number of changes made by head coach Rob Penney.

The one change to the back-line sees Johne Murphy take the place of the injured Simon Zebo on the wing and in the pack Penney introduces O’Mahony as well as Damien Varley, BJ Botha, Donncha O'Callaghan.

Munster: Felix Jones, Keith Earls, Casey Laulala, James Downey, Johne Murphy, Ian Keatley, Conor Murray; Dave Kilcoyne, Damien Varley, BJ Botha, Donncha O'Callaghan, Paul O'Connell, Donnacha Ryan, Niall Ronan, Peter O'Mahony (c).

Replacements: Mike Sherry, James Cronin, Stephen Archer, James Coughlan, CJ Stander, Cathal Sheridan, JJ Hanrahan, Denis Hurley.

Connacht coach Pat Lam has made three changes for Saturday’s Heineken Cup encounter against Zebre (1.35pm). 

The Westerners travel to Parma in Northern Italy to take on the Italian side looking to bounce back after last weekend’s unlucky defeat to Saracens.

Matt Healy returns on the wing, while Samoa international James So'oialo is named at full-back. The 24-year-old versatile back was brought on at inside centre last week at the Sportsground in what was his first Connacht appearance.

Up front, Galway-born Andrew Browne replaces the injured John Muldoon at blindside flanker.

Speaking ahead of the trip to Italy, Lam said: "Losing John Muldoon to injury, along with Eon McKeon and Willie Faloon, was a huge blow to our back row. But Andrew Browne comes in as a straight replacement at six and has plenty of experience in that position.

"Matt Healy comes back in after injury and we Iook forward to seeing him continue the form he showed in the opening weeks of the season.

"James So'oialo starts in his preferred international position of 15 which gives Gavin Duffy a well-deserved break and a chance to make an impact from the bench. And Craig Ronaldson gets a second start at inside centre after such an encouraging performance against Saracens.”

Connacht: James So'oialo, Danie Poolman, Robbie Henshaw, Craig Ronaldson, Matt Healy, Dan Parks, Kieran Marmion; Brett Wilkinson, Sean Henry, Rodney Ah You, Michael Swift (c), Craig Clarke, Andrew Browne, Jake Heenan, George Naoupu.

Replacements: Jason Harris-Wright, JP Cooney, Ronan Loughney, Aly Muldowney, Mata Fifita, Paul O'Donohoe, Dave McSharry, Gavin Duffy.

Ulster scrum-half Ruan Pienaar makes his first start of the season for Ulster in tomorrow’s Heineken Cup Pool 5 game against Montpellier at Stade Yves du Manoir (3.40pm).

Pienaar’s inclusion is one of two personnel changes to the side that beat Leicester Tigers at Ravenhill last Friday.

Man of the match from the Tigers game, Roger Wilson, moves from blindside flanker to Number 8 as Nick Williams misses the game with a calf injury. Robbie Diack is promoted from the bench to start at 6.

All Black prop John Afoa is named as a substitute and is in line to make his first appearance of the season for Ulster having recovered from the calf injury that has kept him out since the summer.

Ulster: Jared Payne, Andrew Trimble, Darren Cave, Luke Marshall, Tommy Bowe, Paddy Jackson, Ruan Pienaar; Tom Court, Rory Best, Declan Fitzpatrick, Johann Muller (c), Dan Tuohy, Robbie Diack, Chris Henry, Roger Wilson.

Replacements: Rob Herring, Callum Black, John Afoa, Lewis Stevenson, Iain Henderson, Paul Marshall, Stuart Olding, Michael Allen.