Former Wallabies coach Eddie Jones says Australia should explore other options at scrum-half and has urged selectors to give centre Matt Giteau a go.
Gregan has won 124 caps for Australia
George Gregan was heavily criticised for his display in the Wallabies' unconvincing win over South Africa.
"I would not rule George out straight away, but there has to be another option," said Jones.
"Sam Cordingley is an option, and they should definitely look at Matt Giteau. He's an outstanding half-back."
Giteau has established himself as a centre or fly-half for the Wallabies but started his career as a scrum-half.
He was selected as a scrum-half for Australia's 2002 tour to Argentina and Europe, but he has never played in the number nine jersey for the Wallabies.
Gregan extended his world record of caps to 124 against South Africa, but has been lambasted in the Australia media with several newspapers demanding he be dropped.
He also overtook John Eales' Australian record of 55 Tests as captain.
Jones suggested it may be time for Gregan to step aside with the World Cup just over a year away, but the player has insisted he wants to lead Australia out in 2007.
"There definitely need to be changes - if changes are going to be made to senior players, they really need to happen now," added Jones.
Gregan has survived several calls for his international career to be brought to an end, particularly during the Wallabies' run of seven straight Test defeats last year.
The Wallabies meet New Zealand again in Auckland in a fortnight, before concluding the tournament in Johannesburg on 9 September.