New Zealand suffered a setback on Friday on the eve of their Rugby Championship opener against Australia with hooker Nathan Harris sustaining a serious knee injury.

Harris ruptured knee ligaments at training, ruling him out for the rest of the season and making way for Codie Taylor to start in Saturday's Test in Sydney.

The injury has forced the All Blacks' hand, with the usual starting hooker Dane Coles called up to the reserves bench as he makes his recovery from a rib injury.

Coach Steve Hansen said Coles would play as many minutes as required.

"If something happened in the first minute, he'll get the 80, no problem," Hansen told reporters.

"The reason we didn't play him was because of the type of injury he's got, they tend to niggle on so if we gave him the extra week he wouldn't have that problem.

"Now we don't have that luxury so out he goes when the time comes."

Hansen said a replacement for Harris would be decided when the team returned home next week.

All Black skipper Kieran Read admitted it was a distraction but the earlier than expected availability of Coles would not weaken the team.

"I guess it is a little bit of a distraction late in the piece that you don't want," Read said.

"But a guy like Dane Coles who's vastly experienced just comes onto the bench and Codie has had plenty of preparation so things just roll on from our point of view."

Harris is the second All Black to succumb to a knee injury this week after centre George Moala tore a medial ligament on Monday, ruling him out for at least the first two matches of the Rugby Championship, which doubles as a Bledisloe Cup Test.

Code-hopping superstar Sonny Bill Williams is already out for the entire championship after tearing an Achilles tendon at the Olympic Sevens tournament in Rio last week.

The All Blacks, who have held the Bledisloe Cup against Australia since 2003, have the advantage this year of two home Tests to follow Sydney's opener.

The All Blacks haven't won in Sydney since 2013 and the team has spent all week in the city preparing for the Test.

"In terms of the Bledisloe Cup, a first game is pretty crucial," Read said.

"We know the significance of playing in Sydney and a Bledisloe Cup game is always a massive occasion.

"We know how tough it's going to be as it always is with these two sides and it's going to be a big game."

Source: AFP