All Blacks coach Steve Hansen has brushed off recent criticism of Sonny Bill Williams saying the second five-eighth has been doing the hard work on the field and remains valuable off the pitch.

The 32-year-old Williams has signed on until the 2019 Rugby World Cup but young players such as Ngani Laumape, Anton Lienert-Brown, Jack Goodhue and Jordie Barrett have stepped up as real contenders for his spot this season.

Hansen has defended Williams' recent performances of telling media ahead of the third Bledisloe Cup test that the two-time World Cup winner has done a fine job returning from injury at last year's Rio Olympics.

"Here's a guy who's come off an Achilles injury. A notoriously slow injury to come back from," Hansen said.

"He's playing well. When he's a flashy player everyone moans about him being too flashy and that he doesn't do the hard work, at the moment he's doing all the hard work and probably not as much of the other stuff that people get excited about."

Hansen said Williams was also making an impact off the field.

"He's in the leadership group, he's leading well. He has a major influence on the young guys and training habits etc. He's getting down and dirty and doing the hard work and we're quite happy with him. He's trying to make good decisions and sometimes like all players he gets it right and sometimes he doesn't.

"He's always been a player that been loved by you blokes or hated by you blokes. It's a 50-50 split and when he does things wrong all the haters get on top of it and when he does things right all the good guys get on top of it. But he's a good international rugby player and we're quite comfortable with him," Hansen added.

Yesterday Wallabies Karmichael Hunt scoffed at any hint that the impact of Williams is waning at 32 by saying the All Blacks dangerman is still "every coach's nightmare."

In his most recent test, the Springboks did one of their best jobs of limiting the impact of his 11 gallops when powerhouse Malcolm Marx twice forced penalties over Williams at the tackle.

The best reflection of the mature Williams is being more than happy to play his role to win Tests when other backs like Reiko Ioane, Beauden Barrett and Damian McKenzie are the dazzlers.

"Sonny is Sonny ... he's a special player," Hunt said of the two-code star.

"His off-load game is unparalleled because when he's getting balls away falling to the ground or from the ground it's beauty to watch."

For anyone other than an opponent in a Bledisloe Cup Test that is.

The effort, precision moments and heart to the near-miss 35-29 loss to the All Blacks in Dunedin in August doesn't give the Wallabies a three-point headstart at the kick-off on Saturday.

"All the hard effort starts again and with Sonny that means putting the body on the line every time," Hunt said.

Regardless of what homework you do, he'll always be coming back at you for 80 minutes ... that's his make-up.

"He's a coach's nightmare. What makes his off-loading game so dangerous is playing good defence on him but also never leaving those running lanes spare either side of him where his teammates time their runs in support."

- With AAP