The former All Black, Australian coach and New Zealand assistant coach told The Rugby Paper that Robertson knew what was expected of him and how to rediscover the All Black's on-field magic.
"I never did the All Blacks as head coach...but I wouldn't have minded being in charge of all that personnel.
"Scott has that privilege now but has earned the right.
"As far as I am concerned, New Zealand needs his authenticity. They need an injection and he's the guy to do it.
"It's not going to be plain sailing. It will be hard. He knows that, and his heart rate is probably going up right now. He will have them pumped up for England, that's for sure.
"But he will be good for the game, good for the All Blacks, and it's an exciting time for him and the fans.
"He knows what the All Blacks need. It's about maximising and not minimising. And he will do that. He helps players and teams to engage. That's what comes out in the wash when it gets difficult."
Deans said his success in Super Rugby showed he is a good coach. He is creative and doesn't dwell on things.
"He knows how the whole of New Zealand can react when the team wins or loses. But he's tough. He had a long, successful playing career in a tough position...He will be excited about what the challenge is, what the role needs and what lies ahead."
Former England and British & Irish Lion, Jeremy Guscott, said in his Rugby Paper column that the tourists have an opportunity to catch the All Blacks short.
England had two weeks to prepare after their 52-17 win over Japan, which was a bonus. They are also meeting a side that has not played since last year's Rugby World Cup final.
"What team gets the All Blacks after they have gone so long without playing a match?
"It has to be one of the most opportune moments for an England team to take on the All Blacks – and if you look at it objectively, why can't England win?
"The most obvious reason is if they go into their shells and lose all the momentum they gained in beating Ireland, then producing a good performance against France, and backing it up three months later with a big win over Japan.
"You cannot get carried away, of course, because New Zealand very rarely lose at home, and hardly ever lose at Eden Park, Auckland, the venue for the second Test. Set against that, England appear to be in a decent place, with plenty of positive signs."
Guscott said New Zealand had always been his favourite other side.
"It is because I admire their relentless search for success, and believe that a coach like Wayne Smith is a rugby guru.
"In New Zealand, rugby is the be-all and end-all, but the Kiwis are fairly balanced and certainly appreciate good rugby from other teams. So, I admire the All Blacks, full stop.
"It should be a great series, because the Crusaders under Robertson's stewardship played some outstanding rugby, and his All Blacks will be meeting an England side taking another step in their attacking evolution."