Ulster v Glasgow Warriors, Today (5.05), Kingspan Stadium, Sky Sports 4
Former Leinster Sub Academy lock Alan O'Connor, from Skerries, has made a sound enough impact at Ulster to keep his place beside South African Franco van der Merwe in what will be a litmus test.
This is undoubtedly the tie of the round as leaders Glasgow seek to protect their 100pc record at one of the most testing, at times intimidating, venues in the PRO12.
The Northern Province have finally sorted out their coaching issues going forward, Neil Doak holding the reins until Les Kiss is ready to return in 2015.
The former scrum-half Doak admitted this week that there is an attraction in taking over at a club where they have almost made a habit out of making finals without winning them.
In an Ireland context, the placement of Jared Payne at thirteen, opposite the talented Mark Bennett, makes for interesting examination. The Kiwi's inbuilt composure and ability to have time on the ball are diminished in the centre, where physicality and instinct are pre-requisites.
It remains to be seen whether he can make the transition from full-back, a position made for his natural gifts, to the pressure points in the midfield.
Ulster: L Ludik; A Trimble, J Payne, S McCloskey, T Bowe; I Humphreys, P Marshall; A Warwick, R Best (capt), W Herbst, A O'Connor, F van der Merwe, R Diack, C Henry, N Williams.
Glasgow: P Murchie; S Maitland, M Bennett, P Horne, T Seymour; F Russell, H Pyrgos; G Reid, F Brown, E Murray, T Swinson, L Nakarawa, R Harley, C Fusaro, J Strauss (capt).