The 12 players not selected for the 31-player squad - most notably Cory Jane, Charles Piutau, Israel Dagg and Lima Sopoaga - will meet the All Blacks coaches in Wellington tomorrow to discuss why they were left out and what is expected of them over the next few weeks.
Talking a day after Slade left training at Wellington's Hutt Recreation Ground with a minor knee tweak, Hansen said an ITM Cup assignment could quickly turn into a plane trip to England for those on standby.
"It [discussion] is their moment to have a chat about why they're not in the team and the other key message that we've got to get across is that this is our expectation of you going forward," Hansen said.
"There's a possibility you could be on a plane tomorrow. You only have to see how quickly things could have turned yesterday [Slade's slip]. A lot of it will be just between us and them and some of it will be about logistics and so forth. It's just important they can get back to playing really good rugby in the ITM Cup."
Hansen said there was no point basing players in Europe in case of injury during the tournament, as World Cup regulations insisted on a 48-hour stand-down period before a player can join the squad as an injury replacement.
The All Blacks will tomorrow disperse for a trip to different parts of the nation - a repeat of a successful innovation ahead of the last tournament - before meeting in Auckland on Tuesday for their final pre-tournament camp. They will leave for the World Cup next Thursday.
Hansen said his squad for the first game against Argentina at Wembley on September 21 (NZT) was pretty set in his mind.
"We've got a pretty good idea who we're going to start. Obviously with a four-day turnaround [before Namibia match] we're going to have to make some changes for the second one. We know we're playing Argentina and that's probably one of the key games for the pool. We'll try to put as many of our best players out as we can, but we've still got an important game four days later. Some of them might have to back up - probably two or three and then we'll get the rest of them on the park.
"Without telling Namibia what we're going to do, the key thing is working out what's critical... and recovery is something that will be critical as we'll have a large number of people who will - whilst they won't be starting - they will be playing some part of the game, I should imagine. Getting over the game is going to be critical so how often do we train during those four days... it might not be practical to do too much from a physical point of view."
Asked whether he enjoyed World Cups or loathed them due to the extra pressure, Hansen, who coached Wales in 2003, said: "I love them. This is the fourth one I've been to.
"You get to test yourself against everybody. You know everybody you're playing is up for it. Sometimes I wonder in between World Cups how the other nations are driving their bus; whether they are mucking around or whether they are really serious about what they're doing at that time. Without being disrespectful, I guess they are, but they also probably don't have as many expectations as we have on us to win every test match. So for us, the pressure's no greater than it normally is just a bigger box of chocolates at the end of it."
