North Melbourne's round-12 game against Brisbane won't be able to take place in Hobart as the AFL had planned.

"As I have always said, we won't be making any special deals in terms of exemptions for AFL," Tasmania premier Peter Gutwein told reporters.

"There will be no AFL football played in Tasmania for the month of August. We'll continue to review it on a weekly basis."

Gutwein's announcement will come as no surprise to the AFL, North or the Lions after the Kangaroos' round-11 game against Melbourne was shifted from Blundstone Arena to the Adelaide Oval.

Tasmania had already decided to keep its borders closed to people travelling from Queensland until at least August 14 - a day before the Roos-Lions game.

North Melbourne and Hawthorn are contracted to host games in Tasmania this year but there could be as few as two home-and-away rounds left to be played in September.

Meanwhile, AFL crowds at the Adelaide Oval will be cut back to a maximum of 10,000 people after South Australia recorded two new coronavirus cases.

South Australian Premier Steven Marshall has announced a range of restrictions after the state's new COVID-19 cases on Monday.

About 18,000 people have been attending recent Port Adelaide and Adelaide home games but hopes the legal capacity would be increased later in the season have been dashed.

"We set ourselves a goal to go up to 25(000), but we have never actually been at 25,000," Marshall told reporters.

"We're working with the (Adelaide Oval) stadium management authority and we're looking at revising their COVID management plan.

"It's likely to rest at around 10,000 outdoor spectators, plus a number of people in venues that are contained at the oval."

Ticket-holders to Monday night's game between Port Adelaide and the Western Bulldogs won't be impacted.

Adelaide Oval will also host Adelaide's clash with Melbourne on Wednesday night.

Australian Associated Press