One thing will become evident as soon as the All Blacks run on to Yokohama's Nissan Stadium pitch for the Test against Japan on Saturday and the visiting coaches will be quietly excited about it.

It is the size of their pack and in particular the dimensions of their two starting props.

Loosehead prop Tamaiti Williams stands 1.96m (6 foot 5 inches) tall and is 144kg. Tighthead prop Pasilio Tosi, preparing to start a Test for the first time, stands 1.93m (6 foot 4 inches) tall and is even heavier at 146kg.

The pair, both converted No.8s and therefore with advantages in terms of footwork and ball skills in open play, are set for long and fruitful international careers because if there is one fundamental truth that has remained constant in rugby it is the importance of size.

It says something that the pair are significantly heavier than Ofa Tu'ungafasi, the 1.93m and 129kg loosehead prop on the bench against Japan.

Indeed, the sight of Williams, Tosi, hooker Asafa Aumua (109kg), and locks Sam Darry 2.03m (6 foot 8 inches) and Patrick Tuipulotu (1.98m 6 foot 6 inches and 120kg) on the pitch this week took even head coach Scott Robertson aback.

"It is a big pack — watching them training today … when you've got two 6 foot 6-plus locks and your front rowers are over 6 foot 3 as well — it's a big forward pack," Robertson said.

Williams, who is playing his 15th Test, is 24 years old. Tosi, playing in only his third, is 26. Darry is 24 and is about to play his sixth Test.

The trio will be expected to help the All Blacks dominate Japan's set piece, particularly the scrum, an area where Robertson and forwards coach Jason Ryan will believe there is still room for improvement.

The scrum got the All Blacks out of jail to a certain extent against England in July.

In the two Tests against Argentina it didn't get a chance to impose itself during the defeat in Wellington because, bizarrely, there were only four scrums in the game and none in the first half, but it showed its potential in the victory over the Pumas at Eden Park.

It held its own against the Springboks in South Africa. The one disappointment for Robertson and Ryan may have come in the two victories over the Wallabies during which the All Blacks tried but failed to dominate the Aussie pack — and credit must be given to Kiwi scrum coach Mike Cron for that.

It's clear Williams and Tosi are behind Ethan de Groot and Tyrel Lomax on the prop pecking order. The 28-year-old Lomax, 1.93m tall and 127kg, has developed into one of the best tightheads in the world, while de Groot, a 26-year-old with similar physical dimensions, is ideally suited to blunting opposition front rows as a starter.

With tighthead Fletcher Newell, 24, also in the mix — and on the bench for Saturday's Test — it means the future for Williams and Tosi may be in the form of the All Blacks' own Bomb Squad, a large and dynamic pair of demolition experts.

It would appear the ideal place for the pair to develop their craft in the knowledge they will be hitting their physical peaks in time for the 2027 Rugby World Cup.

Their continued development, added to the depth the All Blacks already have in the front row, is a huge positive for Robertson and company, because while technique can be coached, size cannot, and Williams and Tosi have that in abundance.

Bigger Tests loom for the All Blacks this year, but on Saturday we may get a glimpse of the future.

All Blacks team to play Japan in Nissan Stadium, Yokohama, on Saturday, kick-off 6.50pm, is:

1. Tamaiti Williams, 2. Asafo Aumua, 3. Pasilio Tosi, 4. Sam Darry, 5. Patrick Tuipulotu (c), 6. Samipeni Finau, 7. Sam Cane, 8. Wallace Sititi, 9. Cam Roigard, 10. Damian McKenzie, 11. Mark Tele'a, 12. Anton Lienert-Brown, 13. Billy Proctor, 14. Sevu Reece, 15. Stephen Perofeta.

Reserves: 16. George Bell, 17. Ofa Tu’ungafasi, 18. Fletcher Newell, 19. Josh Lord, 20. Peter Lakai*, 21. TJ Perenara, 22. David Havili, 23. Ruben Love*.

* Potential debutant