Before he gets to London with his 36-player squad, though, Hansen has to perform something of a juggling act.
He will take a 27-man squad to Tokyo today, with nine players heading to Paris later in the week to start early preparations for the second test against France. They arrive in the French capital on Saturday, with the rest of the All Blacks arriving a day later.
Tony Woodcock, Luke Romano, Sam Whitelock, Kieran Read, Liam Messam, Israel Dagg, Cory Jane, Julian Savea and "apprentice" Ardie Savea will travel directly to Paris, with Aaron Cruden travelling to Tokyo late in the week for promotional duties.
The original plan was to send Richie McCaw and Dan Carter straight to Paris, but their lack of recent game time because of injuries - a knee and calf problem for McCaw and a shoulder injury for Carter - means they will start in Tokyo.
"Initially we were going to use the Japan game to give Kieran Read more time as a skipper but because of Ric's time out of the game he's had more time probably than we wanted. It's actually a reversal now, we need Ric to get game time so Reado's going to go to Paris - he's skippered eight test matches now, it's working well, that combination, so it's more important that Ric gets the game time."
Hansen added of Carter: "If Dan didn't come to Japan it would have been eight weeks since he'd been involved - it's a tall order to go straight into a French test without any rugby."
The uncapped Frank Halai, Luke Whitelock and Dominic Bird could all get game time against Japan, with Wellington prop Jeffrey Toomaga-Allen, yesterday included as a replacement for Canterbury's Joe Moody, who broke his leg in his team's 29-13 ITM Cup final victory over Wellington at the Cake Tin the night before, an outside chance.
Hansen said an important task would be to keep everyone engaged. "The biggest challenge is that we're in one place with one mind because we've got a few extra guys. The guys who will be involved on the Saturday, it's about the other 14 guys being there and not thinking about the next week when they might be playing."