George Gregan's demise in world rugby is highly over-rated according to long-time combatant Joost van der Westhuizen.

The pair have been going toe to toe in international rugby for nearly a decade and the veteran South African halfback said the Wallabies captain still had plenty to offer.

The Australian No.9 has come in for heavy criticism over the past 12 months for the speed of his delivery and his ineffectiveness in attack leading into the World Cup.

Gregan is under enormous pressure to perform in the defending world champions' opening match on Friday against Argentina in Sydney.

However, the former Springboks captain said Gregan fully deserved his spot ahead of understudy Chris Whitaker.

"I think he is still a superb player, I still think he is one of the best and he has a lot of offer to Australia," van der Westhuizen said.

"There is nothing wrong with his game, that is my personal view."

Van der Westhuizen, who returned to the national side this season after being overlooked last year, admitted he did not expect to play in a third World Cup.

"I still don't think my game is on top form but there is a lot I still can do and a lot I want to do," he said.

Brought to you by AAP © 2024 AAP