After eight years of certainty and solidity, it was inevitable the All Blacks would endure a period of volatility and fluidity in their midfield selections.
There was always a danger that after Ma'a Nonu and Conrad Smith established themselves as the most experienced centre partnership in history that the All Blacks would have to play around with their options when those two retired in 2015.
There was no ready-made partnership to take over. There was no obvious stand out in the No 13 jersey ready to replace Smith and while Sonny Bill Williams was the heir apparent to Nonu's No 12 jersey, he was rendered unavailable in 2016 due to sevens commitments and then injury.
The coaches came into 2016 relatively open-minded and were forced to be more so like that due to an endless injury toll that saw them have to dig deep into the talent pool and swap their combinations almost week-by-week.
But by the end of the year they had formed the view that Williams and Ryan Crotty, as their two most experienced individuals, was the best available combination and in 2017 those two played nine tests together and it would have been more but for injury and suspension.
The plan coming into this year was to enhance that combination and have it operating with an instinctive flow coming into World Cup year.
But again injury has scuppered those plans and Williams and Crotty will be paired together for the first time this year in Buenos Aries.
And they will play their first test of 2018 under a different set of circumstances than had they both been fit to play earlier in the year.
In the seven tests the All Blacks have so far played, Jack Goodhue has featured in five and established what many suspected - that, despite his relative youth, he's one of the most composed players in New Zealand and one of the best decision-makers with it.
There was not a hint of nervousness or inhibition when he made his debut against France in Dunedin and his contribution in the two Bledisloe Cup tests went beyond all expectation.
What surprised about Goodhue, although given how he played for the Crusaders throughout this year probably shouldn't have, was his versatility in the sense he was able to be a brick wall defender and smash it up gainline runner as well as astute distributor, creator and finisher.
Not many centres have that same range: that ability to play others into space and exploit it themselves while being a selfless and rigid defender.
And now, a year out from the World Cup, there is genuine pressure on the Williams-Crotty partnership.
Goodhue has been that good. His ability to run straight and hold the defence was a big reason the All Blacks scored so many counter-attack, turnover tries against the Wallabies.
Not everyone will have appreciated his role in some of the All Blacks' spectacular length of the field tries and how his timing made all the difference.
But the coaching staff did and Crotty, whose own standing in the game has been built on his lack of errors and composure, is now in a dogfight for that No 13 jersey.
So much so, that it is possible there will be a selection surprise before the end of the year.
Goodhue, having played nearly every game for the Crusaders and then five tough tests in succession was effectively not available for selection in Buenos Aries.
"We were trying to give him a rest the week before and we couldn't give him one [because Williams was a late withdrawal from the Wellington test due to tonsilitis]," said Hansen. "He had to have a rest at some point and it just so happened to be this one."
Everyone can read into that what they will in regard to whether Goodhue is being rested this week with a view to returning to action next week in Pretoria.
It's possible, but more likely the selectors, if injuries allow, will give Williams and Crotty a consecutive run together.
It's their usual style to give the senior men some time to respond to a challenge laid down by an emerging force and there is no question that there will need to be a response.
Crotty, for all the goodwill he has stored in a six-year test career that has seen him establish himself as a world-class operator, will need to use the ball as assiduously as Goodhue.
Crotty will need to be as adept at manipulating the defence to create space for others and he'll need to make every tackle count.
Goodwill doesn't last in the All Blacks and while Crotty has by no means lived off it or dropped his own high standards this year, Goodhue has played so well that the selectors need a compelling reason to keep him out of the starting team.