There is a growing interest for a wildcard weekend from AFL clubs, as league CEO Gillon McLachlan hasn't ruled out implementing a playoff-style round as early as 2018.

The AFL continues to work on a number of different fixture formats, with the 17-5 and 18-4 styles at the top of the list.

While an overhaul of the fixture isn't likely to be made until the 2019 season, a wildcard round could be on the cards next season, with up to four clubs playing off in a bid for the remaining two final spots.

In this example, 7th would play 10th and 8th would play 9th in the weekend of the pre-finals bye, to determine which two sides would go on to play September football.

"There was more interest in a wildcard round leading into finals than I thought there would be," McLachlan said.

"That had, I wouldn't say universal, but a significant level of support. That was the thing that was probably most surprising."

"It was two games and there are a couple of variations on that."

McLachlan added that while a 17-5 fixture system will likely be at least two years in the making, he didn't rule out a big change in 2018.

"On substantive fixture reform, I think it's unlikely for 2018. The broader stuff would be 2019 but the wildcard would be for 2018," he said.