Ulster v Leinster, 7.35pm
Leinster’s season hangs by a thread while Ulster must negotiate a difficult finish to the regular schedule if they are to retain their place in the top four of the Guinness Pro12.
Currently in third place, a win would see Ulster seal their top-four spot and strongly boost their prospects of a home semi-final. Defeat will mean a nervous few weeks.
Ulster have Munster and Glasgow to come in the closing two weeks and could do with heading into those games knowing their play-off place is secure.
Leinster have a much easier set of fixtures in those rounds with Treviso and Edinburgh next up.
But the maths at this stage mean they must hope that either the Ospreys lose twice or Ulster three times in the next three weeks. Even a 14 or 15-point haul from the final three rounds might not be enough.
It is a slim chance but given the context, it is no surprise that O’Connor has held nothing back in his team selection. There are a few switches designed to introduce some freshness, sensible given that fatigue is likely with Leinster having played 100 minutes against Toulon as recently as Sunday.
But marquee forwards Mike Ross, Cian Healy, Sean O’Brien and Jamie Heaslip are asked to go the well again and the result may well hinge on their capacity to produce dominance in the scrum and breakdown battles.
Ulster have also picked a strong XV and will also expect a big performance in front of a home crowd.
Stable set-piece and some momentum from the back line are a must.
Ulster are immeasurably better with Ruan Pienaar at the tiller and have quality across the back line with Tommy Bowe and Craig Gilroy particularly dangerous on the wings.
But even they must have some material to work with.
They are likely to get it, too, as it is very unlikely that Ulster will put in a shambolic set-piece in the manner of Toulon. Their energy and organisation should also be several notches higher.
The quality in the Leinster side means a surprise cannot be discounted - a big performance from someone like Sean O’Brien could easily upset the balance of this match.
But Ulster, well-rested and with just enough quality in the pack, should be able to see off early Leinster pressure and coast to victory in the final quarter.
Pro12 Prediction:
Ulster 23-15 Leinster
Ulster: L Ludik; T Bowe, J Payne, D Cave, C Gilroy; P Jackson, R Pienaar; C Black, R Best (capt), W Herbst, D Tuohy, F Van der Merwe, I Henderson, C Henry, R Wilson.
Replacements: R Herring, A Warwick, B Ross, R Diack, C Ross, P Marshall, I Humphreys, S McCloskey.
Leinster: R Kearney; Z Kirchner, B Te'o, G D'Arcy, L Fitzgerald; J Gopperth, I Boss; C Healy, R Strauss, M Ross, D Toner, M McCarthy, S O'Brien, D Ryan, J Heaslip (capt).
Replacements: S Cronin; J McGrath, T Furlong, B Marshall, J Murphy, E Reddan, I Madigan, D Fanning.