All Blacks coach Steve Hansen has showed his class by taking the time to wish Wallabies and Brumbies star Christian Lealiifano all the best as he begins a battle with cancer.

Hansen briefly put aside his team's fierce rivalry with Australia in a pre-game interview with Fox Sports to send a message to Lealiifano, recently diagnosed with leukaemia.

"Just before I go. Chris if you are out there watching this, from the All Blacks, we just wish you a speedy recovery, mate, and we are thinking of you," he said.

It comes just days after a number of the Wallabies shaved their heads in an act of support the Brumbies back.