Taylor has hovered on the edge of this group since 2012 and while he is not quite in the same class, he showed himself to be imminently capable when he answered a late call up to make his debut against the Wallabies in 2013.
Given the typical imbalance between their stature and the physical demands of the position, first-fives are prone to injury - something New Zealanders know all about.
While the All Blacks were forever nervous about Carter's well-being between 2005 and 2011, they haven't had to be so edgy in this regard for the past few years.
Even a calamitous injury toll as struck in 2013 which saw Carter, Cruden and Barrett ruled out of the second Bledisloe test, wasn't much of a drama. Taylor stepped in and Slade supported from the bench and the Wallabies didn't get a look in.
But next year, the picture won't be so rosy and the process of finding the next generation of No 10s will begin again.
Lima Sopoaga will suddenly be viewed in a different light. There is plenty to like about his game and he's added necessary components to his portfolio in the past two years.
He'll be scrutinised now and next season to see if there is enough about him to be considered a test option and he'll go onto the 'maybe' pile.
McKenzie, who turns 20 tomorrow, is the more intriguing prospect. He may well look like he'd snap in a stiff breeze, but he's so far proven unbreakable in Super 15. And he's tested himself hard to see whether he is.
Against the Blues in Hamilton he was faced with a charging Frank Halai. Not many players would relish the prospect of throwing themselves at the 110kg wing - especially not one conceding 30kg as McKenzie was. In he went, though, hard and low and Halai was toppled, and it's moments like that which have the top brass thinking the Chiefs youngster has the goods for test football.
His bravery is the added bonus, rather than the driving rationale to see him in that light. McKenzie has all the boxes ticked - he has a runner, he can kick his goals and implement the game plan.
He's got all the components to be successful - he just needs time on the park during Super Rugby to bring everything together.
The progression the All Black coaches most likely had in mind was for McKenzie to play Chiefs, New Zealand Under-20s and Waikato this year, more with the Chiefs and Waikato next and then possibly a place on the All Blacks end of season tour to Europe, which may include a game against Racing Metro in Paris.
But Slade's decision to join Pau has created a different picture and McKenzie may be the man to fast-track into the squad from June next year when Wales will be in New Zealand for a three-test series.
The All Blacks will need a third first-five option next year. That will be to cover for injury; it will be to develop for the future and it will also be because of their belief they are a better team when they have two first-fives accommodated in their backline.
Opposition sides that are fixated with the rush defence and squeezing the space on the field are best played, reckon the All Blacks, with more than one first receiver. They are best played when the All Blacks have more kicking options. While that combination has in the past been viewed as best from a No 10/No 12 pairing, it is now more likely to come from No 10 and No 15.
McKenzie, like Barrett and Slade, appears to be equally at home at fullback and like the former, he's a player who screams out as being in possession of abilities that if carefully harnessed and developed, will see him become a long-term test player.
"As we all see, he has got a fair bit of brilliance about him," says Chiefs coach Dave Rennie. "He's got the ability to cut teams open and at times, he is so brave, he gets himself into a bit of trouble.
"We have been encouraging him to link with some of the big guys to let them carry a bit of pill rather than have him running into the big men. He's a great little man so we have to manage him and decide whether we let him go to the Under-20 World Cup which will take him out of a few weeks of our footy. A little bit of that will be based on how we are from an injury point of view.
"He's a great young man. He's got a great skill-set, still learning a bit about fullback - he's played a lot of 10 - but he's got something pretty special that as he matures and understands the role, could be quite sensational."