Six Nations champions Wales must prepare to face one of the most physical sides in world rugby when they play South Africa, says Rob Howley.
Howley was at Ellis Park to watch New Zealand's 38-37 win over South Africa in Johannesburg on 5 October.
The Wales assistant coach believes his side face a physical examination when they host the Springboks on 9 November.
"We need the mental intensity and mental preparation to be ready for a week Saturday," said Howley.
"Having had the experience of going out to watch South Africa and New Zealand in Jo'burg... we are probably coming up against one of the most physical sides in world rugby.
"When you look at the performances of late in the Autumn series, we have been hugely disappointing.
"When this side played last it was against England and, I believe after that performance, we will have to go up another level to have any chance of beating the Springboks."
Wales are the reigning 2013 Six Nations champions and had 10 players in the British and Irish Lions side which beat Australia 41-16 in the third Test to clinch the series 2-1 in July.
Wales have only beaten South Africa once in the 26 meetings between the two countries, and that was the opening game at the Millennium Stadium in 1999.
But the Springboks only emerged with a 17-16 victory when the sides last met in Wellington at the 2011 World Cup in New Zealand.
Howley was on a fact-finding mission with Wales team manager Alan Phillips for the All Blacks' victory over South Africa which clinched the Rugby Championship
He spoke to the New Zealand coaching team, including head coach and former Wales coach Steve Hansen, and also spoke to a member of the South Africa coaching team after the game.
Howley says Wales have to be ready for the "intensity and pace" of the game he expects South Africa to play at the Millennium Stadium.
"It was a really informative weekend, having been able to catch up with the New Zealand coaching team and Steve Hansen," said Howley.
"And subsequently on the Saturday after the game, we talked to Steve about their preparation for South Africa and caught up with the South Africa contact coach on the Sunday morning after the event.
"It's just great, as coaches, to talk about rugby and you are still learning as coaches.
"It was a really informative weekend and there is no doubt that game was a special event and a privilege to watch live, with the number of tries scored.
"As I said to both coaches on that night, you would be chuffed if you were attack coach and disappointed if you were defence coach."