The All Blacks need a player who the rest of the world hasn’t analysed to death.
It was four years ago, at Eden Park against the Wallabies, that the genius of Israel Dagg became apparent. It was Dagg who made the miracle run to set up Ma'a Nonu's try and Dagg was the man who pulled the Wallabies defence this way and that.
Back then he was the All Blacks' X-factor - the wild-card element that gave New Zealand an unknown, fresh and dynamic force at fullback.
But what is he now? That's arguably the biggest question to emerge from the team that has been selected to exact revenge on Australia. It would seem that one way or another, the coaches have made up their minds about Dagg. They have, obviously, seen enough in his first three tests to have reached a conclusion about whether they are going to take him to the World Cup or not.
And on this, there are two schools of thought. The first is that he's done enough to provide certainty that he's match fit and with his experience, booming right boot and ability to nudge forward and play first receiver, he has to go to England.
But, in truth, that seems the less likely of the two options. The other conclusion is that the coaches have made up their minds and they don't see Dagg in their World Cup squad.
He's a specialist in a versatile world. He's been steady when others have done more. There's no way on earth that the All Blacks are going to leave Ben Smith at home for the World Cup. Ditto Julian Savea - who should show a marked improvement this weekend.
So that's two of four outside back places locked up. Then there is Charles Piutau - who appeared to be in the bad books earlier this year when he signed with Ulster but has played well enough in recent tests to give everyone a distinct feeling he has to be on the plane to England.
With Cory Jane still in the "who knows" box, the focus has fallen on Nehe Milner-Skudder.
If he had bombed last week, if he had frozen on the big stage, then no doubt the picture would be different for Dagg.
But here's the thing, Milner-Skudder looked a lot like Dagg did ahead of the last World Cup. It was Dagg who ignited the All Blacks when they lost in Port Elizabeth ahead of the tournament in 2011 just as it was Milner-Skudder who was the only undoubted highlight in Sydney.
The All Blacks need that point of difference in the mix. They need a player who the rest of the world hasn't analysed to death and get caught out by.
That was Dagg in 2011, but if Milner-Skudder can provide more of the same at Eden Park and tidy up a few, small parts of his game, it feels increasingly like he's going to be the man to provide the excitement and variation in 2015.
And if Milner-Skudder is in, it most likely means Dagg is out. Tough old business this professional rugby lark, but that's how it has to be if the All Blacks are going to make history and win back-to-back World Cups.