Ben Smith believes the All Blacks' cautious approach to head knocks is the right one even if it means key players are forced to miss Tests.

The full-back, who missed New Zealand's second and third Tests against the British and Irish Lions, will return from an inner-ear issue in Saturday's Bledisloe Cup opener against Australia.

It was initially feared the vice-captain's recent balance problems resulted from a concussion during New Zealand's first Test against the Lions.

Smith, who will take a sabbatical from the sport after two more Tests, noted it was important medics take a conservative approach with any head injury.

"As a player it's great to know your safety is first," he said in Sydney.

"As players we've got hopefully a lot of time when rugby finishes to do other things and at that point we want our health to be right.

"So we can do things with family and not have problems.

"It's really important that it is taken seriously... it's awesome the right things are in place when it (head knocks) happens."

All Blacks hooker Dane Coles will miss this weekend's ANZ Stadium clash with the Wallabies because of a recent head knock.

The world champions' coach, Steve Hansen, indicated Coles is fit and could have played but he'd been ruled out because of serious concussion symptoms suffered earlier this year.

"When I had my problems, he sent me a message to say that his best method was just to stay positive," Smith said of Coles.

"That is what he has been doing.

"I know he has been frustrated with what he has gone though but he's still been really positive and that's all you can do.