"We've got five test matches in 19 days and a squad of 28. You need to make sure you manage combinations so that you get the very best out of all 28 players.
"Over these first two games we want to make sure everybody gets an opportunity to contribute and so we are managing the workload accordingly."
The New Zealand Under 20 team will be looking to continue their form that saw them go through the Oceania Championship undefeated.
"We haven't had a chance to see any footage of Japan play so the focus has been on us. We've been working on our structures in attack and defence and getting them back in place, making sure everyone is really clear how we want to play the game."
The match kicks off at 7am (NZT) and is live on TVNZ Duke.