"It was a tough day. Ireland played well and we learnt lessons from that match. They put pressure on us at scrum time and kicked to the corners well. They played to the conditions and stayed strong for the full 80 minutes. These Northern Hemisphere sides play a different style of footy to us, so we must adjust to that."
The game was played in conditions that were extremely testing at times, and Robertson hopes his young players learn from the experience.
"The weather suited their style of play. We've got a young group of guys that like to play expansive rugby. We don't want to stop that, but need to balance attack with playing to the conditions."
Wales have had a mixed tournament so far, with a narrow 25-26 loss to Ireland followed by an equally tight 10-9 victory over Georgia, but they won't be underestimated.
"Wales always step up. For a lot of these teams, when they play New Zealand, they play their best. So we are expecting Wales to come out firing. It is a knockout game. Lose and you miss out on the semifinals. We have taken a lot of learnings from the Georgian and Irish games and are still in the hunt at this tournament," said Robertson.
New Zealand need to win and win well if they are to have any chance of progressing to the semifinal stage, so the message from the coaching team to the players will be a simple one. "We have a chance to make the semifinals - it's in our hands now. Get out there, enjoy yourself and believe in our systems - from there the scoreboard takes care of itself."
Kickoff is at 4.30am tomorrow, screened live on SKY Sport 1.
NZ Under 20s squad v Wales: Shaun Stevenson, Caleb Makene, Sio Tomkinson, Jordie Barrett, Jonah Lowe, TJ Va'a, Sam Nock, Marino Mikaele-Tu'u, Mitch Jacobson, Fin Hoeata, Hamish Dalzell, Quinten Strange, Sefo Kautai, Leni Apisai (c), Ayden Johnstone
Reserves: Asafo Aumua, Sean Paranihi, Alex Fidow, Isaia Walker-Leawere, Luke Jacobson, Jonathan Taumateine, Stephen Perofeta, Malo Tuitama