Tupou Vaa’i’s injury is a huge blow to the All Blacks.

Only a handful of established All Blacks have maintained or improved on their previous standards since Scott Robertson and company took charge. Vaa’i is one of them.

You can add Ardie Savea, obviously, Cam Roigard, Codie Taylor and probably Tamaiti Williams too. The names stop springing to mind after that.

You see, I have a theory about Robertson and his coaching staff and that it’s that they don’t make very good, good or even adequate players better. No, they kind of just make them worse.

Instead of improving what they’ve got, the All Blacks’ brains trust defaults to picking new blokes and hoping their athleticism and enthusiasm fill the void in tutelage.

Rieko Ioane appears to be yesterday’s man now. Sevu Reece and Anton Lienert-Brown the same. A bit like David Havili before them. Caleb Clarke’s hardly first-choice and Billy Proctor’s poised to become an afterthought as well. You don’t get much runway with these guys. Just ask Christian Lio-Willie.

Leroy Carter, Simon Parker and Fabian Holland are flavour of the month at the moment. Just as Wallace Sititi was this time last year.

Quinn Tupaea is new to this coaching group as well, and basking in the warm glow of the coaching staff’s approval for the time being.

I don’t know about you, but I thought New Zealand’s Rugby Championship campaign was unsatisfactory on the whole.

The team was okay against Australia and did take a test off South Africa. But losing to Argentina and imploding against the Springboks was a really poor look.

If I was enthused about anything during the competition, it was Savea, Roigard and the new boys.

That worries me in a couple of senses: first, that most of the senior pros hardly fired a shot and, second, that there’s a limited supply of other potential debutants.

Because, let’s be fair, the modus operandi isn’t to get more out of what you’ve got, but to select someone else entirely.

Are any of the Barretts better for their involvement with this coaching staff? How about Damian McKenzie? Will Jordan’s so good that, like Savea and Roigard, it almost doesn’t matter who’s in charge.

I mention those guys because they always get picked, whenever fit. Others are not so fortunate.

Samipeni Finau and Asafo Aumua should probably be making alternative plans. Injuries meant Pasilio Tosi got a bit of gametime in Perth on Saturday, but he’s a peripheral figure too.

I see this selection group throwing a lot of darts at the board and, yes, they do hit the odd bullseye, with Holland definitely being one.

But will we see much of George Bell again? What about Luke Jacobson, Ethan Blackadder and Dalton Papali’i? Are Ollie Norris, Du’Plessis Kirifi and Ruben Love going to kick on?

Or should they emulate Mark Tele’a and Harry Plummer and try their luck elsewhere?

It’s easy to opt for bright, shiny new toys. The potential’s limitless, at least until they’ve played a couple of games and it becomes clear there’s one or two flaws to tidy up.

A scattergun selection approach is one thing, but I do harbour concerns about how quickly players are discarded and suspect the problem isn’t necessarily them, but the quality of coaching they receive.

There’s sufficient talent in the All Blacks’ squad – and hopefully always will be – to ensure they continue to win more games than they lose.

But, at the risk of labouring the point too long, this is a team winning on ability alone. I’m not seeing anything to suggest there’s much method behind it.