The scrum-half, who undwent surgery on Wednesday, said he played "a game and half" with a torn knee tendon after injuring himself midway through the Wallabies clash.

"I thought I tore it against Australia," Van der Westhuizen said.

His right knee was already heavily strapped in the World Cup

"There was a lot of discomfort but I decided to play the full game against New Zealand.

"I'm obviously very disappointed but what can I do?"

Van der Westhuizen is expected to spend at least two months resting before the rehabilitation process can begin.

Springbok physiotherapist Wayne Diesel said: "We evaluated Joost before the tournament and his knee was stable enough to play.

"Joost went to see a specialist when we returned and he recommended surgery."

It is the third successive year that Van der Westhuizen has ended a trip to the nothern hemisphere with a long-term injury.

He missed the majority of the 1998 and 1999 Super 12 seasons following groin and knee injuries sustained against France and England respectively.