Leinster will have to reshuffle the pack this week as they prepare for the annual Christmas interpros - with Ulster at the RDS up first.
Leo Cullen will be without Johnny Sexton, who will see a specialist after sustaining a knee injury against Northampton.
But backup number ten Ross Byrne's availability is up in the air after he picked up a dead leg over the weekend - Ciaran Frawley could be set to start for the Pro14 champions.
Ulster will be boosted after nine of their squad were named in Andy Farrell's 45-man 'stock-take' next week and will hope to upset the odds in Donnybrook.
Here's all you need to know about the game:
When is it on?
The match is set for kick off at 7:35 PM on Friday, December 20.
Where is it on?
The RDS in Donnybrook will host the game
What channel is it on?
The match will be shown live on Eir Sport 1, with coverage beginning at 7 pm.
You will also be able to follow the match on the Irish Mirror Sport's live blog.
Teams
Leinster: Rob Kearney, Fergus McFadden, Tommy O'Brien, Robbie Henshaw, Cian Kelleher, Harry Byrne, Jamison Gibson-Park, Peter Dooley, Seán Cronin, Andrew Porter, Scott Fardy, Josh Murphy, Will Connors, Scott Penny, Max Deegan
Replacements: Bryan Byrne, Cian Healy, Jack Aungier, Oisín Dowling, Josh van der Flier, Hugh O’Sullivan, Ciarán Frawley, Conor O’Brien
Ulster: Rob Lyttle, Craig Gilroy, Matt Faddes, Angus Curtis, Angus Kernohan, Bill Johnston, David Shanahan, Andrew Warwick, Adam McBurney, Tom O'Toole, David O’Connor, Alan O’Connor, Matthew Rea, Nick Timoney, Greg Jones.
Replacements: John Andrew, Kyle McCall, Ross Kane, Jack Regan, Azur Allison, Jonny Stewart, Stewart Moore, Ethan McIlroy.
Betting Odds
Leinster 1/20
Draw 35/1
Ulster 17/2
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