He believes the game's potential is "limitless" and that future administrators will have different ideas on how to grow it.
"In 2030 you could be talking about an international presence … the world might be a smaller place then, who knows?" Demetriou said.
"You could be talking about Tasmania being entrenched in the competition and another team in Western Australia. I just know that it (the AFL) won't look like it does today.
"If we had have been 20 or 25 years ago when the AFL was formed and the West Coast Eagles came in, if people had have talked about the competition looking like it does today with 18 teams perhaps in 2012 ... we would have all asked for psychiatric treatment."
Demetriou will oversee the introduction of Gold Coast (2011) and Greater Western Sydney (2012) in the next two years as the AFL moves towards its 18-team competition.
With that will come the difficult task of deciding on an appropriate length for the home and away season, as well as the make-up of the finals system.
Debate has already started as to whether the competition should preserve its final eight or create a new system that could possibly include nine or 10 teams.
Demetriou said the League would seek as much consultation and feedback as possible to ensure the best - and safest - transition.
"It's a big decision because regardless of what we think, 16 teams into 22 weeks, we know it's not a perfect scenario … but it's a system that's worked very well," he said.
"Crowds have grown, ratings have grown, revenues have grown, memberships are up … six of the last seven premiers have been different teams, so it's worked by and large so we wouldn’t want to get it wrong.
"Having 18 teams, we need to still capture the same magic that the 16 into 22 captured because it's remarkable in the finals how many times the top-four teams have got through to the preliminary finals.
"So let's hope that we get that part right. Fingers crossed that we will."
