Blue-chip tight-five can help to deliver hat-trick of derby prizes for Cullen
On the day the Christmas tree is supposed to come down, Leinster can hoist their flag as the undisputed top dogs of Irish provincial rugby by completing their third win in 11 days over their rivals.
Leo Cullen once again shuffles his pack and Josh Murphy's inclusion means that he has used 37 players across the three interpros in a remarkable show of strength.
That that figure doesn't include injured players like Joey Carbery, Adam Byrne, Seán O'Brien, Rhys Ruddock, Dave Kearney and Jamie Heaslip, the suspended Cian Healy and the rested Isa Nacewa is testament to their squad depth.
Certainly, this is the strongest tight-five he has picked yet and after watching Ulster being bullied by Munster's largely second-string pack at Kingspan Stadium on New Year's Day, they'll hope to have the edge in that department.
If they can get on top there, then the game will open up for them and while James Lowe is given the day off there are plenty of talented backs ready to make the most of their opportunity given Cullen will have to pick a best XV for the Champions Cup game against Glasgow next weekend.
Restoration Ulster's pack effort has been boosted by the return from injury of Rory Best (pictured) and the restoration of Iain Henderson to the second-row.
Although the second-half recovery saved the northern province's blushes on Monday, a similar first-half effort would lead to things getting very ugly very quickly at the RDS.
"They're going to be hugely disappointed with that first half, so with new lads coming back in they'll be geed up for this game," Devin Toner said.
International Rugby Newsletter
"It's an interpro, it's always massive for every team, for us as well. But look at us in the table - they're six points behind us and if we win we go ten points ahead of them.
"They'll look at that, so it's huge for them, then with the lead-in to Europe, they're going to want to get a good performance in, we're not expecting anything soft.
"You always want to back your own maul, we have huge confidence in ours but you have to be smart about it as well, you have to take the points when you can. It's how the game goes, whether you go for the corner or not, you make that decision on the pitch. We've a lot of confidence in our maul so hopefully we can get a few chances."
Jack McGrath captains Leinster at loosehead in an all-Ireland front-row, with Toner joining Scott Fardy in the engine room.
Behind them, there is a relatively new face in Josh Murphy who starts on the blindside with Jordi Murphy and Jack Conan well-established at this stage.
McGrath will fancy his chances against Rodney Ah You who retains the Ulster No 3 jersey despite being called ashore at half-time last week and if Leinster can get the upper hand and prevent their visitors from getting good ball, then they'll hope to cause young scrum-half Johnny Stewart a host of problems.
The Ireland U-20 is highly rated, but if he is not given the platform then it could be a difficult day on his first senior start. Christian Leali'ifano will have a big role to play in guiding him through, but the pack must protect him if he is to thrive in his step up.
Opposite that duo are Jamison Gibson-Park and Ross Byrne who played so well at Thomond Park, while Cullen has the comfort of having Johnny Sexton in reserve just in case.
Robbie Henshaw and Garry Ringrose will hope to find their groove with Jordan Larmour ready to light things up from full-back. Ulster's back-three is not too shabby either, but they'll need the ball.
Leinster's tight-five will bank on denying them possession and, if they do that, the hat-trick of wins should come their way to set them up well for Europe.
LEINSTER - J Larmour; F McFadden, G Ringrose, R Henshaw, B Daly; R Byrne, J Gibson-Park; J McGrath (capt), J Tracy, T Furlong; D Toner, S Fardy; Josh Murphy, Jordi Murphy, Jack Conan. Reps: S Cronin, E Byrne, A Porter, M Kearney, M Deegan, N McCarthy, J Sexton, N Reid.
ULSTER - C Piutau; A Trimble, D Cave, S McCloskey, J Stockdale; C Leali'ifano, J Stewart; C Black, R Best (capt), R Ah You; P Browne, I Henderson; M Rea, S Reidy, J Deysel. Reps: R Herring, K McCall, W Herbst, A O'Connor, N Timoney, J Cooney, J McPhillips, T Bowe.
Ref - N Owens (Wales)
Leinster v Ulster,
Live, Sky Sports, 5.35