With the experiment of playing Matt Giteau in the position seemingly over, the 34-year-old former skipper looks certain to figure strongly in the Wallabies' World Cup preparations.
And that is something Fisher, Gregan's provincial coach at the ACT Brumbies, is in strong agreement with.
"Knowing him and knowing the other players, and his qualities, I certainly believe that (Gregan at scrum-half) to be the best for the team," Fisher said.
While selectors are likely to stick with Gregan, Fisher believes they will look outside their current 30-man squad in before finalising a number of other contentious positions for the World Cup touring party.
He reckons prop Nic Henderson, hooker Tatafu Polota-Nau, lock Al Campbell, number eight Jone Tawake, and utility backs Ryan Cross and Clinton Schifcofske, are among those still firmly in contention.
"I think there's a number of guys who have the opportunity to push their case in some pretty competitive positions," he said.
Wallaby selectors have experimented with different starting combinations against Wales and Fiji, but Fisher is sure a full-strength side will be used against New Zealand and South Africa in the Tri-Nations tournament.
"I think you'll find that the Tri-Nations will reveal where they (the selectors) want to go and you'd be looking to run your number one backline to start all those games, I'd suggest," Fisher said.
"I think in the end you need your quality players feeling good about themselves and good about the people around them, and I think that's where they'll end up."