The loss of Sonny Bill Williams is more annoying than it is disastrous for the All Blacks.

They will cope without Williams - knowing they have both Seta Tamanivalu and Anton Leinert-Brown waiting to step up - but would rather be going through the Rugby Championship with him.

They also know that they have the supremely talented Charlie Ngatai in the background - a player they will recall for the end of year tour as long as he recovers from concussion symptoms and regains his match fitness.

Williams' Olympics sevens teammate, Rieko Ioane is also on the All Blacks' radar, probably more as a wing option but longer term as a centre.


Still, for all the emerging talent at his disposal, All Blacks coach Steve Hansen had pencilled in a plan for Williams and his integration into the squad during the Rugby Championship before his Achilles injury suffered in the sevens Rio loss to Japan.

Williams would have joined the squad ahead of their return test against the Wallabies in Wellington on August 27. Hansen had hinted that if Williams had returned from Rio in good shape, he'd have been in contention to either start or come off the bench in Wellington.

And no doubt, given Williams' experience and his role within the All Blacks' leadership group, he'd have become the starting No 12, probably by the third test of the campaign against Argentina in Hamilton in early September.

But that's not going to happen with the medics forecasting that Williams will be out of all rugby for anything between six to nine months.

"He will be out of rugby for six to nine months," New Zealand Rugby Union chief executive Steve Tew told Newstalk ZB from Rio.

"He will be unavailable for the All Blacks and Steve [Hansen] and the other coaches will have to start thinking about a replacement. Whoever gets that chance will make the most of it."

In terms of midfield starting options for the Rugby Championship, that remains a three-way choice between Ryan Crotty, Malakai Fekitoa and George Moala.

First cab off the rank to be called in to officially replace Williams in the 32-man squad is presumably Tamanivalu, who was an original pick in the June squad before losing his place for the Rugby Championship to Moala.

He was left out amid concerns his defensive positioning needed work and his general awareness was not quite as high as the coaches had hoped. With ball in hand he was he powerful but the risks outweighed the rewards. But because he's had two tests and some exposure to the All Blacks' systems, he's probably a better bet to be called up than his Chiefs' teammate Leinert-Brown who has impressed all season with his solid running, strong defence and decision-making.

Probably, but no definitely as Leinert-Brown is a natural No 12 and therefore a direct replacement for Williams. That may not have a huge bearing, however, as Crotty and Fekitoa have played tests at both second-five and centre.

Moala played at second-five for the Blues last season and although he has experience in the role, Hansen said in June that it would be unlikely the All Blacks would use him in the role.

Both Tamanivalu and Leinert-Brown trained with the All Blacks last week and it is expected that Hansen will announce Williams' replacement on Friday - although it may be sooner.