June can be a problem - with players coming out of Super Rugby in a different mindset about what qualities matter and others having failed to meet basic conditioning standards.
The camp is really about ensuring everyone understanding what they will have to do physically and mentally to hit the ground running in June.
"It's a well-being camp, let's call it that," Hansen said. "Which will be great because it will allow them to go into Super Rugby in the best nick that we can possibly get them into at that point.
"Sometimes you get the luxury of allowing players to go through the June series and getting them in the right condition. They have got to turn up in the right condition.
"They are probably going to be the best Lions team to come down for a long time, with what they have got to select.
"We have put a lot of work into what we want to and know we are going to have to redevelop our game a little bit. The important part is transitioning these guys back into their franchises, making sure they get a good offseason so they are fresh and ready to go. We just can't afford anyone to be behind the eight ball in June."
The recent results in the November tests have only reiterated how physical players in the North are how much work they have put into their pass and catch since the last World Cup. Not only did Ireland beat the All Blacks, they beat the Wallabies too and probably Scotland should have had they stayed calm in the last minute.
England are unbeaten this year and a side drawn from the best player from those countries and Wales is going to have to considerable talent.
As a general rule, the All Blacks will let individuals play for their clubs against the Lions where they can - but those games scheduled for nearer the test series, decision haven't yet been made about who can and can't be released.