Former England and Lions back Will Greenwood has praised the depth of talent in New Zealand rugby.
Spending time as an assistant coach with the Barbarians, Greenwood worked with several players on the fringes of international selection.
"One of the great weeks of my fledgling coaching career was when I got invited to be asistant coach of the Barbarians in South Africa under Robbie Deans," said Greenwood.
"I listened to Luke Whitelock, Andy Ellis, Jordan Taufua, Richie Mo'unga, and I just thought geez, no wonder you guys are so good, you just get it. I don't know what 'it' is but your vocabulary and knowledge of the systems you want to run, you just drop them into it.
"Seta Tamanivalu, we gave him a special defensive play called Thunderbolt and we just let him go create havoc in the South African midfield, we'll pick up the system in behind you, just go and be our wildcard, and just the understanding of the guy."
Greenwood had high praise for Hurricanes back rower Brad Shields, and entertained the idea of Shields one day representing England.
"Brad Shields, again, what a player. You want to be careful, I think we just discovered he's got an English passport. If he's got an English passport and he's a back row forward as good as he is, I would be on the phone right now asking if he wants a game at Leicester. We'll find a slot for you. He had a proper engine, he's tough."
The 55-test Englishman believes that New Zealand's depth is the key to success.
"That sort of leads on to the All Blacks. How can you have that many good players not even in the squad of 35?", Greenwood said. "Your depth of talent is outstanding. Your discovery this year of [Anton] Lienert-Brown, I think two reasons you lost in Chicago, no Lienert-Brown and your second rowers were missing and that put you under a whole heap of pressure in the set piece."
Greenwood also commented on Michael Cheika's embattled Australian side, who will take on England this weekend.
"The Wallabies, I think troubled you guys at Eden Park. I know you won 37-10 in the end but the Aussies had that try disallowed at the right hand side and I thought they played pretty well until you blew them away in the last 10-15 mintues.
"The patterns they're running with, I know Coleman won't play this weekend so it'll probably be Arnold and Simmons, maybe Kane Douglas in the second row and Stephen Moore. They run this really clever pod system that we worked pretty quickly with Robbie Deans coaching the Barbarians."
"They're starting to look again like a really competitive Wallaby side."
Greenwood noted the important role a competitive Wallaby side plays in New Zealand's development.
"However much you might dislike them as Kiwis you need a good Wallaby side to keep pushing you guys."
England are missing several key players, and Greenwood rates Australia's chances against the side that have won 13 straight tests.
"George Kruis has been out for a while, he came back in so he's fit again, I get that, Itoje out, Launchbury out, Billy Vunipola out for three months," said Greenwood. "Billy's huge for us, he's as good as Kieran Read, no question. He's an absolutely sensational rugby player."
Greenwood warned that the Wallabies should not be taken lightly, and that the side is vastly different to the one that was swept aside by England earlier in the year.
"England are a really good side, don't get me wrong, but I just think if you're judging the Aussies on how they played against England this summer you're judging the wrong team. They've completely changed.
"There's absolutely no way England will give them a hiding, they are too good a Wallaby side now and they're starting to get back to looking really slick behind that pack."