(Photo Credit: David Ramos - World Rugby via Getty Images)
World Cup-winning coach Jake White is concerned the Springboks has had an overly straightforward run to their semi-final against Wales on Sunday.
"South Africa has had it easy so far. They will know that. They were always going to come second in their pool and then they got Japan," said White, who coached his country to the trophy in 2007.
White believes South Africa's preferred quarter-final opponents would have been France, who lost 20-19 in their encounter with Wales.
"But if you'd told South Africa before the tournament that you'll get Japan in the quarter-finals of a World Cup, they'd have taken it.
"The only time they have been tested, they lost against New Zealand in the pool game so it's difficult to say what they have been like.
"They have been good enough to win the other games but the real test comes now."
Wales have won five of their last six meetings with the Springboks, with their one defeat coming in the RWC 2015 quarter-final. White believes Wales coach Warren Gatland has a steady hand on the tiller.
"I am sure 'Gats' will have been giving it to Wales this week, telling them they were close to going home and they had better get it right this weekend," said White, who has been coaching in Japan.
"The fact they were so pushed to beat France means they will get a massive amount of confidence from that.
"Looking at Dan Biggar's body language when they won, the way he reacted and got the crowd going. That's why I think Wales can do it.
"They've had South Africa's number for a while. What I'd fear as a coach is that Wales weren't great last weekend but they got over the line. That means a lot when you are looking for momentum."