'I was pretty surprised': Foster's verdict on Barrett's red card

All Blacks coach Ian Foster says Jordie Barrett's controversial send-off against the Wallabies on Sunday was proof that the 20-minute red card law should be implemented globally.

Barrett was given his marching orders in the 28th minute of Sunday's 38-21 win in Perth for a studs-to-the-face incident on Wallabies winger Marika Koroibete.

The All Blacks fullback had stuck out his right leg to protect himself after leaping to catch a high kick, and he collected Koroibete flush in the face.

Under normal laws, the red card would have seen the All Blacks reduced to 14 men for the rest of the match.

But under a new experiment taking place in the Bledisloe Cup and Rugby Championships, red-carded players can be replaced after 20 minutes.

Foster didn't believe Barrett should have received a red card in the first place.

But he said the new 20-minute law regarding red cards meant the effects weren't as devastating.

Two years ago, the All Blacks were also dealt a red card in Perth.

The 20-minute rule wasn't in place at that time, and they ended up getting pumped 47-26 by the Wallabies.

"It's why all the SANZAAR countries are pretty united in wanting to carry on this global trial," Foster said.

"We were a keen supporter of that even before the games. Today's event probably justifies it."

Barrett is now facing a potential suspension, but Foster indicated that the All Blacks would fight the charge.

"I was pretty surprised to be honest [that he got the red card]," Foster said.

"We'll go and have a good look at it, but certainly we'll be putting together a case for that one.

"He just lost balance and you could see he tilted and you could see what happened [next].

"I feel for the refs in situations like this, because technically they saw things and they make their decisions. I get all that. Have we got a technique problem – no."

Wallabies coach Dave Rennie is also in favour of the 20-minute red card.

"I think it's good we've got a 20-minute red card at the moment because it's certainly not malicious," Rennie said of the incident.

"Based on law, when you field the ball and you kick your foot out and collect someone in the head, there's going to be repercussions for that.

"I think the decision is probably accurate, and the fact it was only 20 minutes is a good thing."