"He knows he has to go away and get sharper and fitter than he is now, even though he is at the best he has been for quite some time.
"It is something which over a wee period of time we have seen and started to question and when we sat down and talked to him he understood what we were talking about."
His place has gone to another Wellington man, the 21-year-old Perenara who has risen rapidly to the top despite breaking his ankle last season.
Weepu took to Twitter soon after the announcement to reach out to his fans.
"Thanks for the messages of support tweeps!! Always tough, but that's what makes you fight for it even more," he tweeted.
"Congrats to my bro @Tj_Perenara on his selection in to the squats!! Always knew you'd be there brother!! Enjoy it cuzzie! #KidOnTheRise."
Perenara captained the NZ Secondary Schools in 2010 and debuted for Wellington later that year, played for NZ under 20s in 2011 and got his initial Super 15 chance last season.
Perenara replaces Weepu in the 28 man squad in which Joe Moody has been picked to cover for Wyatt Crockett as he recovers from his knee injury with Jeremy Thrush, Francis Saili and Frank Halai as extras to help with training selections.
"He (Weepu) has been an outstanding contributor to New Zealand rugby and his greatest hour was through that World Cup in 2011 when he really stood up and played particularly well," said Hansen.
Weepu took a lot of pressure of the young five eighths when Dan Carter was injured.
"He has been a great servant to the All Blacks and been an important part of our team for a long time both on and off the field. Like all of us there will be a time when it is time to make the change and the three selectors as a group feel this is the time."
There was no thought of keeping him as an impact player if he could not play the game the All Blacks wanted.
Perenara had similar skills and was a younger, fitter version and when he played well, showed many of Weepu's skills.
It was time for Perenara and also a challenge to Weepu to see if he could reconfigure his game.
"We were happy with how Aaron Smith has bedded in and he is reasonably experienced and we need to tell POW to sort out the issues and young TJ can have a crack," said Hansen.
Another regular All Black Victor Vito has also missed the cut. He was a great athlete but he needed to play with "freedom, aggression, intensity and physicality but it just hasn't come.
"So we'd like him to step out and work on his game in the ITM Cup."
Others like Liam Messam and Jerome Kaino had done that and they hoped Vito could do the same.
Hansen lauded the rugby played in the Super 15 final but thought the Brumbies were undone eventually by their travel schedule.
That and the character of the Chiefs to play for 80 minutes helped decide the match.
"It confirms that when you get the culture right and you get people playing well you can achieve anything with the quality of the players. You are getting good players who are playing like great players because they are playing for each other. It's a real tribute to them."
FORWARDS
Hookers: Dane Coles, Andrew Hore, Keven Mealamu
Props: Wyatt Crockett, Charlie Faumuina, Ben Franks, Owen Franks, Tony Woodcock
Locks: Brodie Retallick, Luke Romano, Samuel Whitelock
Loose forwards: Sam Cane, Steven Luatuam, Richie McCaw, Liam Messam, Kieran Read
BACKS
Halfbacks: Tawera Kerr-Barlow, TJ Perenara, Aaron Smith
First five-eighths: Beauden Barrett, Daniel Carter, Aaron Cruden
Midfield backs: Ma'a Nonu, Conrad Smith
Outside backs: Israel Dagg, Charles Piutau, Julian Savea, Ben Smith
The Investec Rugby Championship - All Blacks Tests
1. Australia (ANZ Stadium, Sydney, 8.00PM, Saturday 17 August)
2. Australia (Westpac Stadium, Wellington, 7.35PM, Saturday 24 August)
3. Argentina (Waikato Stadium, Hamilton, 7.35PM, Saturday 7 September)
4. South Africa (Eden Park, Auckland, 7.35PM, Saturday 14 September)
5. Argentina (Estadio Ciudad de La Plata, La Plata, 7.40PM, Sat 28 September)
6. South Africa (Ellis Park, Johannesburg, 5.00PM, Saturday 5 October)
