Jannie du Plessis has revealed sports psychologists that worked with IndyCar drivers have South Africa on track to tackle the might of the All Blacks in their Rugby World Cup semi-final this weekend.

The Springboks have slowly grown in confidence since their humbling to Japan at the start of the tournament, but face the toughest challenge in rugby when they line up against world champions New Zealand at Twickenham on Saturday.

The big prop – and qualified doctor – explained how sports psychologists, who had worked with Indycar drivers trying to avoid deadly situations, have the Boks in the right frame of mind.

The key is to have minds fixed on where you want to go rather than worry about a crash.

“They lose control and they think ‘don’t go into the wall, don’t go into the wall, don’t go into the wall’, and then they drive into the wall and they die,” he said on Monday.

“What they said is that when you are in a pressure situation you should think about where you want to go and not where you do not want to go.

“If you lose control you don’t want to focus on the wall, but rather look for the lane where you want your car to end up and the fatalities are much less after that,” added the 32-year-old veteran of 68 Tests.

“Making mistakes against a team like New Zealand, they can probably score five tries in 10 minutes,” said du Plessis.

“If you focus on not making mistakes, unfortunately it’s human nature if you say ‘don’t drop the ball’, then you drop the ball.”

The All Blacks crushed France 62-13 in a lopsided quarter-final in Cardiff last weekend. By contrast, the Springboks had to work far harder to see off Wales 23-19 at Twickenham.

Du Plessis, brother of South Africa hooker Bismarck, highlighted New Zealand’s killer instinct.

“When they stuck the knife in, they didn’t pull it out, they turned it and made the French feel the full wrath of their performance,” he said.

Du Plessis also took a philosophical approach as to how the Springboks bounced back from the greatest upset in World Cup history.

“I’ve thought a lot about the Japan game,” said du Plessis.

“A friend of mine showed me a band called The Melvins that used two drummers to lay a good foundation.

“If you look at them, you only have to go back to what works for you and your basic thing that keeps the team together and lays a good foundation.

However, he wasn’t convinced the music was inspiring for everyone.

“The band is heavy metal — not that I am into that sort of music… It’s the type of music that will scare your kids.”