Attendances have been banned at all but a handful of Scottish games since March last year and the Pittodrie supremo has been one of the most vociferous in his calls for crowds to return in some capacity to help clubs stuggling finances during the pandemic.
The answer received gives hope that supporters could be back once the vaccination programme expands and more of the public are inoculated against Covid-19.
Addressing Cormack’s question on BBC’s Off The Ball programme, Professor Leitch urged caution with all but the top two tier’s of mens’ football in abeyance since the start of January – a move that was extended to mid-February this week.
Professor Leitch added: “Crowds are much less predictable. I would hope by September the whole country will be vaccinated - 9m doses of vaccine, that's huge.
"It's a massive logistical exercise, and then we will have to see what the virus does. We will have to see if we have managed to not import the virus again with travel restrictions. People are going to have to pay some cost to get more freedom – there are crowds at the Australian Open tennis this week because they have paid a price of international travel to get domestic freedom.
"If we get all of that right as a nation, that's not just the government, it's also all the people, then yes, I think there could be crowds of some description in September."
Clubs in the Highlands were permitted socially distant spectators as part of the area’s Tier One restriction level late last year, however no crowds are currently permitted with the Scottish mainland currently placed in Tier Four.
Aberdeen, who have frequently called for crowds to be allowed back to games, were one of two early season test cases to trial the return of crowds to SPFL games, however Scottish football fans support their teams from home via online video streams.