CHRISTCHURCH (AFP) - New Zealand head coach Ian Foster is demanding further improvement from the All Blacks against an in-form Argentina on Saturday (Aug 27) in the first match since his job was saved by his side's rousing win against South Africa.

Foster on Thursday named an unchanged New Zealand team for the Rugby Championship clash in Christchurch, while the Pumas announced a beefed-up backline to meet the physical challenge of the All Blacks.

New Zealand ended a run of three straight defeats with the 35-23 victory in Johannesburg just under two weeks ago.

A few days later the New Zealand Rugby board voted unanimously to retain the under-fire Foster, despite the All Blacks winning just two of their last seven Tests.

"We're clearly wanting to work on that Test being a level for us," said Foster after naming the first unchanged All Blacks starting side for four years.

"Whilst it was a great result, we still know there's a lot of things we could have done better. After a strong performance, we want to make sure that we really focus on backing that up and growing from that."

Foster is expecting a stern examination from Argentina, who lead the Rugby Championship standings after two rounds following their 48-17 demolition of Australia in San Juan.

Pumas coach Michael Cheika made three starting changes to add bulk to his backs after choosing to omit a handful of experienced players for the two-Test visit to New Zealand.

Strapping backs Matias Moroni and Lucio Cinti start in place of two seasoned stars - centre Jeronimo de la Fuente and wing Juan Imhoff respectively.

"New Zealand have a big backline, so we've got some big players there to maybe counter that," said Cheika.

"This team is a combination of what we saw from the last game and the chance to see a few different things. It's good competition (for places) at the moment."

A lone change in the pack has Joel Sclavi starting at tighthead prop in place of Francisco Gomez Kodela while Cheika has changed all five forwards on his bench in a bid for "new energy from the finishing team".

Argentina are chasing their first win on New Zealand soil, a feat achieved last month by Ireland, who won twice to also secure a maiden series triumph.

Foster is adamant the All Blacks have progressed since that series, which was marred by a Covid-19 outbreak, injuries and suspensions, and was followed by a defeat to the Springboks in Mbombela.

Their backs-to-the-wall victory in Johannesburg left Foster hinting he was close to pinning down his first-choice team.

"The onus is on the players to go out on to that park to perform at a level that this team needs to perform. If they keep doing that, then it does make it hard to change," he said.

There is one change on the bench, with fly-half Beauden Barrett ruled out by a neck injury and replaced by uncapped utility back Stephen Perofeta.

Foster said Barrett was "quite stiff" after a knock in training but could be in contention to play in next week's Test against the Pumas in Hamilton.