'It's the physicality, they're bigger men': Midfield test awaits All Blacks

While Ian Foster has searched for his ideal midfield combination this year with Jack Goodhue sidelined for the season, the Springboks have continued to build with their established pair of Damian de Allende and Lukhanyo Am.

The pair of South African midfielders are in top form, with Am in particular making big defensive plays after an impressive Lions series that saw him contain the likes of Elliot Daly, Chris Harris and Robbie Henshaw.

Speaking on the Aotearoa Rugby Pod, Crusader halfback Bryn Hall praised Am's work as 'fantastic' in their high pressure system which ask the centres and wingers to fly up off the line a lot of the time.

"He was fantastic in that British & Irish Lions series, more so around his defensive reads, being able to put line speed pressure on teams," Hall said.

"I think the way with the South Africa's defence is, with him playing so high with Kolbe and Mapimpi, it's a real confidence boost when the midfielders make good decisions. Am has been doing that consistently.

"I've really enjoyed De Allende as well, he brings a real good go-forward off their line out and mauls. They had a lot of penalty advantages and they played a lot through him, playing 12 and him carrying.

That type of confrontational approach will put the spotlight on the All Blacks midfielders in The Rugby Championship, where current second five David Havili will have to provide support on the inside to the likes of Richie Mo'unga and Beauden Barrett.

The 'big battle' for the All Blacks will be dealing with the 'bigger men' in the Springboks centres and the physicality they bring.

"They've played a British & Irish Lions series together and been really good and strong. That test match against Argentina on the weekend was good as well so I think it's going to be a great challenge for the All Blacks and the likes of David Havili moving forward," Hall said.

"It's the physicality, and they're bigger men. It's going to be a test for our midfield, ALB or Rieko at centre. It's going to be a big battle when we hopefully get the opportunity to play them."

Former All Black hooker James Parsons explained that the pressure system that the Springboks run works in large part because of the decisions of Am.

"The thing I like about Am is, he has the ability to rush up defensively. And I think he's one of the biggest reasons why South Africa is so successful in their defensive system," Parsons explained.

"We all know that 13, I believe, is the hardest position on the field probably to defend. You have to connect with those inside, but the wingers outside can sometimes be 50-50, in that backfield in that pendulum play.

"But what Am does so well, is he gets up, he almost says 'do you want to throw an intercept? You are going to have to throw it over me which will give me time to recover', which he does so well.

"But when he gets up there and their numbers are down, he has the ability to slide as well. His work rate to cover that outside channel once the ball has gone there is outstanding.

The former Blues hooker highlighted Am's work in the second test against the Pumas, where Am made a try-saving play just by being there at the end of the movement and an opportunity came up to snatch away possession.

"You saw that in the 80th minute when he got back and intercepted that ball. The Argies just bobbled it and he sort of just got it, but he didn't give up on the play. And that's the biggest thing he's doing so well defensively.

"He never gives up on the play. He works extremely hard to split with De Allende, so they've got both sides of the field and they're looking after and marshalling the troops inside them.

"There is a lot of stuff he does that doesn't actually involve him doing an action, that forces the opposition to do something and play into their hands and go back into their big boys."