The All Blacks trounced the Pumas 39-0 on the Gold Coast on Sunday to tighten their grip on top spot on the table midway through the southern hemisphere competition.
Bottom-placed Argentina, who started with back-to-back defeats away to world champions South Africa, slumped to their third successive loss and have looked a shell of the team that stunned the All Blacks in the Tri-Nations last year.
But Barrett feels the New Zealanders can ill-afford to be complacent at Lang Park.
“They’re going to be a different team come this Saturday,” he told reporters in a video call on Tuesday.
“Probably turn up with a little bit more of an edge after the performance on the weekend.”
The All Blacks were hard to fault on Sunday but Barrett said they had identified plenty of areas for improvement, one being the lineout after the Pumas’ success in disrupting their set piece.
“We’ve got a plan,” he said. “We’re going to have to adjust to the way they defend. We can’t get too carried away with trying to jump on their big, tall men.”
While still under Covid-19 restrictions, the All Blacks have enjoyed a taste of freedom on the Gold Coast, with players hitting the resort’s beaches in a region where infections are rare.
New Zealand’s largest city Auckland, meanwhile, remains in strict lockdown due to an outbreak, though restrictions have eased in other regions.
Hooker Codie Taylor said his wife and children were doing fine back home but he was worried about his mother.
“Every phone call is different,” he said. “Sometimes you want to talk to her for a long time and sometimes you don’t because it seems like things are about to explode. It’s just part of the reality for us at the moment.”
South Africa’s Franco Mostert, meanwhile, has said the Springboks are in familiar territory with their backs to the wall following the loss to Australia on Sunday, but recent experience has shown them the way out of their current predicament.
The 28-26 defeat means the Springboks likely have to win their three remaining games in the competition to retain the title they won in 2019.
It is not dissimilar to when they lost the opening game of the Rugby World Cup in Japan to New Zealand and were left needing victories in their next six fixtures to lift the trophy. They also lost the first Test to the British & Irish Lions in July after which they had to win the next two to claim the series.
They managed to pull it off on both occasions, and Mostert said they can use that experience against Australia on Saturday, and for their last two games against the All Blacks.
“We know where we are, we have been in this situation before and we know where to go from here,” Mostert said. “The boys are confident and positive, and that is a good sign.”
Bok coach Jacques Nienaber bemoaned his side’s lack of discipline for their weekend loss, and Mostert agreed it was an area of concern.
“We can definitely improve our discipline, it let us down. But we have done our reviews, tomorrow is a new day and we will look to improve on our set-pieces,” he said. “If you give away stupid penalties, teams will capitalise on that. It builds up.
“Credit to Australia, they were hungrier than us, but we will work hard during the week and hopefully we can come back stronger. Rugby is a funny game, you can be at your best and still lose. It is just about the bounce of the ball.”
The Boks have confirmed that reserve lock Nicolaas Janse van Rensburg will return to South Africa for personal reasons and will not be replaced in the squad.