World Cup wings Zac Guildford or Hosea Gear will be favoured to come into the squad as a replacement ahead of Lelia Masaga, Sean Maitland, Rene Ranger or perhaps Andre Taylor.
Kahui damaged his left shoulder in 2009 and had surgery, before he suffered a small fracture in his right shoulder the following year and then had an operation to repair rotator cuff and cartilage damage. Now he faces more surgery and time out of the game.
Injuries have cut into the plans of the All Black panel with prop Charlie Faumuina also out of action before he has started, with a calf injury.
The Chiefs' 20-year-old tighthead prop Ben Tameifuna is likely to stay in the squad as cover because he also has some background on the loosehead side of the scrum.
Five-eighths Daniel Carter was feeling stronger each week and expected to resume goalkicking in games soon.
"We think he'll be fine by the time the test series against Ireland comes round in June," Hansen said. "I'm happy with the way he has been handled, that has been clever."
No 8 Kieran Read should be right after landing heavily on his back in a bungled lineout leap against the Rebels. If he was still sore he might have a scan later this week.
Meanwhile, Hansen will persist with his elder statesmen hookers. Keven Mealamu is 33 and has played 92 tests while Andrew Hore is rising 34 and has played in 62 internationals.
If either fell over, a replacement would come from a group of Corey Flynn, Hika Elliot, Dane Coles or Tom McCartney.
Hansen was keen to work again with the troubled Blues duo of Piri Weepu and Ali Williams and they would be under the pump to produce.
"Piri will be given some guidelines that he has to meet by the end of the second camp and if he meets those he will give himself a good chance of being selected [in the 30 group for the June tests] and if he doesn't, then he makes it hard for himself," Hansen said.
"His issues are all around his fitness. If he gets that sorted we know he is a natural rugby player and a very good one and proven in the test arena.
"He is also a goalkicker but if he is not fit he falls behind the 8-ball," said Hansen.
Williams was a different proposition. There was nothing awry with his fitness or attitude but he had lost confidence and form like many of the Blues. He would be given specific tasks with the All Blacks who would benefit from his 73-test experience.
Without him, Brad Thorn and Anthony Boric, Sam Whitelock was the most experienced test lock with 25 appearances.
"That is not enough for us to go into tests," Hansen said.
Brodie Retallick was the new wave of lock, a classic case of someone who had grown into his huge frame and was energised and playing well.
Similarly Luke Romano's athleticism showed out.
He had the potential to be a strong scrummaging tighthead lock and had nudged out Jarrad Hoeata who was not firing after his chest injury.
