All Blacks coach Steve Hansen has admitted to being "disappointed" and "frustrated" by the lack of communication from Richard Kahui about his departure overseas.

Kahui confirmed last week he was heading to Japan to take up a two-year deal at the end of the Super Rugby campaign, though he has indicated he intends to return to New Zealand rugby, possibly as early as the 2015 season.

If Kahui intends to compete for a place in the All Blacks World Cup squad, he has not exactly got off on the right foot, with Hansen confirming today on LiveSport's breakfast show that he had been in the dark about Kahui's offshore move.

"We have spoken to him about his option to go to Japan," Hansen told the show.

"We were very disappointed with that because he didn't really speak to us, or his agent didn't.

"I always find that a bit frustrating."

Hansen cautioned that Kahui, who would be regarded as a potential successor to Conrad Smith at centre, was taking a risk by leaving the New Zealand game at this point.

"He's talked about coming back, but he, like everybody else, takes a big risk when they leave because there's other people here who have got talent," Hansen said.

"But he's weighed that up and believes he can come back. Hopefully he does and hopefully he comes back and plays to the level that can get him selected."

Hansen admitted he had been surprised by the lack of communication from Kahui's representatives around his opportunities in Japan.

"Normally you hear from them, then you've got an opportunity to discuss it and put a reasonable offer, and if you want them to stay you've got an opportunity to fight to keep them.

"In this case we didn't. But we've discussed that and moved on."

Kahui has been used both as a centre and wing during his 17 tests for the All Blacks, but has had his international career severely curtailed by repeated shoulder injuries.

The Chiefs back loomed as an important figure this season for the All Blacks, both as a midfield option and on the wing, where Cory Jane's absence will open opportunities up for someone in the first part of the season.

- © Fairfax NZ News