England know their hopes of defending the Six Nations could be snuffed out by Wales' suffocating gameplan, says forwards coach Matt Proudfoot.

"They just don't let you go. They get hold of you and just squeeze you," Proudfoot told BBC Sport.

"Our focal point has been to match their intensity."

Proudfoot suffered four successive losses to Wales during his time as part of South Africa's backroom staff, before helping mastermind the Rugby World Cup semi-final victory in October 2019.

A behind-the-scenes documentary of the Springboks' campaign in Japan showed South Africa's players being told in no uncertain terms of Wales' threat, with then-head coach Rassie Erasmus comparing their spirit and toughness favourably to England and Ireland.

"I know how tough it is to go there and how well you have to be prepared," Proudfoot added.

Proudfoot picked out flanker Justin Tipuric, scorer of two tries in the teams' 2020 Six Nations clash, as the best performer in a star-studded Wales forward pack.

"Wyn Jones, Alun Wyn Jones, Justin Tipuric, Taulupe Faletau, Josh Navidi, Aaron Wainwright, James Botham, they are special players, great players, " he added.

"The one really on top of the pile is Tipuric - if you look at his skillset defensively, attacking-wise, what he does in the line-out, he is a special player."

His evaluation was backed up by Courtney Lawes, who toured New Zealand with Tipuric as part of the British and Irish Lions in 2017.

"He is just a great player," Lawes told BBC Sport. "Really consistent, good skills and probably quite an underrated player as well. He gives them a lot around the park."