Australian rugby boss Raelene Castle is standing by under-fire coach Michael Cheika but has hinted that other changes could be on the cards if the Wallabies' results don't improve over the final two Rugby Championship Tests.

The Wallabies arrived in Port Elizabeth on Sunday for a tough away clash with a Springboks outfit riding high off their All Blacks victory. Castle revealed she had been in regular contact with Cheika and Australian captain Michael Hooper during the team's week off and still believed the former Waratahs coach was the right man to lead the team to the World Cup in Japan in just under a year's time.

Raelene Castle met with Michael Cheika and Michael Hooper last week, she said. Credit:AAP

"As I've said on-record before, he has the support of the board," she said. "Yes we're facing some challenging times but he's also doing some work with the environment he's working in to make sure he's got the best people around him and we'll see the performances over the next couple of weeks."

It is understood Cheika is being encouraged to think about enlisting outside help in the form of a technical adviser or trusted rugby mind to help find a way through the team's current malaise, which has seen them win just two of their past nine Tests and drop to seventh in the world rankings.