After the test against Australia in Yokohama on October 27, at least 22 of the 32 players in the main squad will head to Europe with the additional 19 players joining the rump of the party in Tokyo to prepare for the Japan match on November 3.
The additional players, 10 of whom are uncapped at test level, will then return home while the main squad members travel on to London to rejoin their team mates preparing for matches against England, Ireland and Italy.
The extended numbers give Hansen the opportunity to try out personnel and tactics, as well as get used to the conditions they will face at the World Cup in Japan next year.
"We are trying to simulate as much as possible the conditions we will face from a selection point of view for Rugby World Cup," Hansen told reporters in Christchurch today.
"We have two games in Japan that will allow us to simulate the round robin part of the competition with Australia being first up and similar to what we will get against South Africa in terms of top opposition.
"Then the tour heads to Europe where we get two big games against England and Ireland and then a match against Italy who are part of our pool, so the tour has a lot of benefits from a Rugby World Cup point of view."
Hansen will also be able to see which players are able to step up to test level and if they can handle the pressure that comes with playing for the world champions.
"Bringing in the wider squad players allows us to grow our player depth and will expose them to the international arena, which we think will be great for their development and, in turn, will benefit New Zealand Rugby in the long-term," he said today.
The policy has been a consistent one, with the coach routinely bringing uncapped Super Rugby players into training camps ahead of home test matches.
Hansen has also brought along "apprentice" players on end-of-season tours, giving the likes of loose forward Ardie Savea and fullback Jordie Barrett the chance to prove they would not be out of their depth at test level if called upon.
Injuries also resulted in considerable turnover for the side last year.
Hansen took 44 players on their end-of-season tour, allowing flyhalf Richie Mo'unga and centre Jack Goodhue to make their All Blacks debuts and stake their claims for places as regulars in the main squad.
The extended squad named on Monday also includes experienced test players who have slipped down the pecking order like Luke Romano, Nehe Milner-Skudder and Ngani Laumape, giving them a chance to force their way back into Hansen's World Cup plans.
MAIN ALL BLACKS SQUAD
Forwards: Dane Coles, Codie Taylor, Nathan Harris, Joe Moody, Karl Tu'inukuafe, Owen Franks, Nepo Laulala, Ofa Tuungafasi, Brodie Retallick, Sam Whitelock, Scott Barrett, Patrick Tuipulotu, Ardie Savea, Matt Todd, Dalton Papali'i*, Liam Squire, Vaea Fifita, Kieran Read (captain).
Backs: Aaron Smith, TJ Perenara, Te Toiroa Tahuriorangi, Beauden Barrett, Richie Mo'unga, Damian McKenzie, Sonny Bill Williams, Ryan Crotty, Jack Goodhue, Anton Lienert-Brown, Waisake Naholo, Rieko Ioane, Jordie Barrett, Ben Smith.
EXTENDED SQUAD FOR JAPAN GAME
Liam Coltman, Asafo Aumua*, Tim Perry, Angus Ta'avao, Tyrel Lomax*, Reuben O'Neill*, Luke Romano, Jackson Hemopo, Gareth Evans*, Dillon Hunt*, Luke Whitelock, Mitchell Drummond*, Bryn Hall*, Brett Cameron*, Ngani Laumape, Matt Proctor*, David Havili, Nehe Milner-Skudder, George Bridge*.
* denotes uncapped player