With Wales pushing Robbie Deans' men right to the wire in the first Test in Brisbane, the former scrum half has been impressed by the efforts the Grand Slam champions have put in so far, despite their dream of a first win on Aussie soil since 1969 yet to be achieved.
"There's no doubting you can't get much tighter than this series," said Gregan. "There's not much between the sides - eventually the tables will turn but hopefully the Australian team will be thinking it's not tomorrow."
Gregan is expecting the series to conclude with another closely fought encounter.
"I see it very similar to the first two, I think it is going to be really tight and will probably go down to the last 10 minutes where it's going to be in the balance. I think it is going to be a high scoring game. Australia have won both Test matches by narrow margins and I can't see this being any different.
"There's still a lot to play for. Wales stated their case early, they came over here and wanted to be the first Welsh team in over 40 years to win on Australian soil and they have one more chance to do it - they've got one more chance to chase history and conversely Australia has a chance to close out the series."
The full video interview with George Gregan can be viewed exclusively on http://supporters.wru.co.uk/welcome.php
Australia: 15 Kurtley Beale, 14 Adam Ashley-Cooper, 13 Rob Horne, 12 Pat McCabe, 11 Digby Ioane, 10 Berrick Barnes, 9 Will Genia, 8 Wycliff Palu, 7 David Pocock (captain), 6 Scott Higginbotham, 5 Nathan Sharpe, 4 Sitaleki Timani, 3 Sekope Kepu, 2 Tatafu Polota Nau, 1 Benn Robinson.
Replacements: 16 Stephen Moore, 17 Ben Alexander, 18 Rob Simmons, 19 Dave Dennis, 20 Michael Hooper, 21 Nic White, 22 Anthony Faingaa.
Wales: 15 Leigh Halfpenny, 14 Alex Cuthbert, 13 Jonathan Davies, 12 Ashley Beck, 11 George North, 10 Rhys Priestland, 9 Mike Phillips, 8 Ryan Jones, 7 Sam Warburton (captain), 6 Dan Lydiate, 5 Alun Wyn Jones, 4 Bradley Davies, 3 Adam Jones, 2 Matthew Rees, 1 Gethin Jenkins.
Replacements: 16 Ken Owens, 17 Paul James, 18 Luke Charteris, 19 Justin Tipuric, 20 Rhys Webb, 21 James Hook, 22 Scott Williams.
You will be able to follow tomorrow's third and final Test between Australia and Wales on www.wru.co.uk/live