Peter de Villiers feels only the pressure of playing on home soil could get to tournament favourites New Zealand.
Despite dominating the sport the All Blacks have struggled at the World Cup with their only triumph coming in the inaugural tournament in 1987.
Defeated finalists in 1995, New Zealand were dumped out at the quarter-final stage last time but once again they are considered the favourites to lift the Webb Ellis Trophy in October.
Despite the All Blacks surrendering their Tri-Nations crown to Australia, de Villiers believes they will prove extremely difficult to overcome on home soil, although he knows the pressure of playing in front of their home supporters could prove too much.
"To beat the All Blacks in New Zealand will be very tough and they remain favourites for the World Cup," said De Villiers.
"But if the pressure in New Zealand gets to the team, then it could affect the way they play."
De Villiers was a keen observer of Australia's victory in the Tri-Nations last Saturday and praised Robbie Deans' men for getting the better of the All Blacks.
"Australia got it right last Saturday - they cut down on the space available to New Zealand because both teams like to play expansively," said De Villiers.
"The Wallabies concentrated more on their forwards and were brutal in contact and you could see they were very focused by the way they stared down the haka."