James Mortimer 30.May.2012Getty Images
The Wallabies most recent match against the All Blacks was a 20-6 loss in the World Cup semi-final, but Gregan felt the win over New Zealand at Suncorp Stadium in the final match of the Investec Tri Nations was indication of a "bridged gap".
Gregan, who played a world record 139-tests, told AAP that last season the Wallabies had caught up with the All Blacks.
"I think we can definitely bridge the gap, the gap was pretty much bridged to a pretty big degree last year," Gregan said.
"I think you just have to look back to that final game at Suncorp.
"Obviously they lost a Test match in a Tri Nations series in Auckland, but I think they've shown that they can beat this New Zealand team in the space of the last 12 months.
Gregan also felt that the All Blacks were looking over their shoulder at the Wallabies.
"There's not too much of a gap between the two teams," he said.
"I think the New Zealand team would be aware of that, but nothing beats doing it consistently, so that's the challenge ahead.
Gregan felt that regular success would win the Wallabies back the Bledisloe Cup, with the All Blacks currently on the second longest streak in history in terms of Cup reigns.
"If they do it (beat the All Blacks) consistently they win that big cup back, the Bledisloe, which we haven't had for a long time."