Ireland duo Paddy Jackson and Darren Cave have been included in Ulster's squad for Friday night's Guinness Pro12 tie against Cardiff Blues at Kingspan Stadium.
Having returned from World Cup duty this week, the pair have been named among the replacements, with Neil Doak making just two changes to his starting XV.
After coming back from injury to earn a place on the bench last week, outhalf Ian Humphreys will start his first competitive match of the season.
Leinster head coach Leo Cullen has made seven changes to the starting team that lost away to the Scarlets last weekend as his team welcome reigning champions Glasgow Warriors to the RDS.
Returning players include Ben Te’o and Jack Conan who have shaken off calf and ankle knocks respectively, as do Ireland World Cup players Mike McCarthy and Rhys Ruddock who were late additions to the Irish squad. Ruddock came off the bench in the quarter-final defeat to Argentina.
Among the replacements, Tadhg Furlong is in line to make his first appearance of the season for Leinster having played against Wales and England in the pre-World Cup warm up games and against Romania in the World Cup.
Also among the replacements is Isaac Boss who was called up to the Irish squad after the Scarlets game last Friday following the withdrawal of Jared Payne.
Meanwhile Munster head coach Anthony Foley makes eight changes to the starting team that defeated Glasgow in the last round of fixtures, for Friday night's trip to the Scarlets.
Jordan Coghlan will make his first competitive start for Munster while Ronan O’Mahony is included in a matchday squad for the first time this season.
The only change in the frontrow comes at hooker with Duncan Casey joining Dave Kilcoyne and BJ Botha, while in the secondrow Mark Chisholm moves to five with Robin Copeland making his first secondrow start for the province.
In other news, Munster Rugby have confirmed that Uruguayan prop Mario Sagario has signed a three-month contract with the province.
Sagario, who trained with the squad this week in Limerick and Cork, most recently started in all of Uruguay’s Pool A World Cup games and has made 51 appearances for his country. The 29-year-old tighthead formerly played with French Pro D2 sides RC Massy and Dax.
ULSTER: Louis Ludik; Andrew Trimble, Sammy Arnold, Stuart McCloskey, Craig Gilroy; Ian Humphreys, Paul Marshall; Callum Black, Rob Herring (captain), Wiehahn Herbst, Lewis Stevenson, Franco van der Merwe, Roger Wilson, Sean Reidy, Nick Williams.
Replacements: John Andrew, Andrew Warwick, Ricky Lutton, Peter Browne, Willie Faloon, David Shanahan, Paddy Jackson, Darren Cave.
LEINSTER: I Nacewa (captain); G Ringrose, B Te'o, N Reid, F McFadden; C Marsh, L McGrath; M Bent, A Dundon, M Moore; R Molony, M McCarthy; R Ruddock, J van der Flier, J Conan.
Replacements: J Tracy, P Dooley, T Furlong, D Ryan, D Leavy, I Boss, R Byrne, C Kelleher.
MUNSTER: Andrew Conway; Stephen Fitzgerald, David Johnston, Denis Hurley, Gerhard van den Heever; Tyler Bleyendaal, Cathal Sheridan; Dave Kilcoyne, Duncan Casey, BJ Botha; Robin Copeland, Mark Chisholm; Dave O'Callaghan, Jordan Coghlan, CJ Stander (captain).
Replacements: Niall Scannell, James Cronin, John Ryan, Dave Foley, Shane Buckley, Tomás O'Leary, Ian Keatley, Ronan O'Mahony.
