How well the combination of Byron Karaitiana and Isaac perform in midfield could, in fact, have a big bearing on the result of tomorrow's fixture.
Buller rate their own midfielders highly and they have been the launching pad for the bulk of their most dangerous attacks through their Heartland campaign.
If Karaitiana - who has been one of the big success stories in the Wairarapa-Bush squad in recent games - and Isaac can keep them under wraps they will be doing their side a huge favour.
It will be important too that Karaitiana and Isaac give their three-quarters a flying start in attacking situations. If there is a more dangerous attacker in Heartland rugby at the moment than wing Paul Tikomainavalu this writer hasn't seen them while fellow winger Cameron Hayton, who has had more than his share of injury hassles, did enough against King Country to suggest he is about to find the form which won his national Heartland selection last year.
Add to them the speed and sheer cheek of fullback Nick Olson and Wairarapa-Bush have a back three fair oozing try-scoring potential.
The Wairarapa-Bush forwards can anticipate a hard day at the office against a Buller pack containing a fair measure of experience. There was though a pleasing intensity about the Wairarapa-Bush play up front last weekend and a repeat of that would probably be enough to ensure their backs are given an ample supply of quality ball to do their thing.
It is interesting that three of the Wairarapa-Bush players who made a big impact off the bench against King Country, prop Jonathan Fuimaono, hooker Jamie Hunt and utility forward Sam Marshall-Wilson, will start there again in Westport. There is no doubt, however, they will all enter the fray in the relatively early stages of the second half and it is reassuring to know that the team effort won't be compromised in any way when that happens.
The Wairarapa-Bush team is: Nick Olson; Paul Tikomainavalu, Tapaga Isaac, Byron Karaitiana, Cameron Hayton; Glen Walters; Zeb Aporo; Nathan Iro; Johan van Vliet, Lachie McFadzean, Clark Butcher, Johnie McFadzean; Finnbarr Kerr-Newell, Richard Puddy, Campbell Lawrence. Reserves: Joseph Sio, Titapu Pairama-Lewington, Nathan Hunt, Jamie Hunt, Jonathan Fuimaono, Wiremu Grace, Sam Marshall-Wilson.