Speaking at an event looking ahead to the tournament, McCaw, a two-time World Cup-winner, said he expects Michael Cheika's team to come good at the tournament, despite having won just four of their 13 games last year.
"Knowing Australians like I do, they are competitive, hugely competitive and they will get themselves in good situation to compete," McCaw, who led the All Blacks to victory over the Wallabies in the 2015 final, told Reuters.
"They have got ability to win games now against everyone so you don't want to write them off at all.