Three AFL games have been relocated while five clubs have departed Queensland because of the state's coronavirus lockdown.
Saturday's Gold Coast-Melbourne and Essendon-Sydney fixtures were postponed, while Sunday's GWS-Port Adelaide contest was also affected.
The Suns will now take on the Demons at Marvel Stadium early on Sunday afternoon as part of a double header, with the Giants to face the Power later at the same venue - while Essendon will host Sydney at the MCG.
All three games will be behind closed doors.
The fixture switch means there will be no games played on a Saturday night for the first time since round 12, 1997.
Queensland's lockdown began at 4pm local time on Saturday, with the government ruling out all professional sport.
"There will be no football matches," Queensland chief health officer Jeanette Young said.
"No community sport, no professional sport, nothing for the next three days."
Melbourne players were on a flight to the Gold Coast on Saturday morning when the south-east Queensland lockdown was announced.
They landed in Brisbane but didn't leave the tarmac before returning directly to Melbourne
GWS, Sydney and Essendon had been operating out of temporary bases in Queensland.
All three teams, plus Gold Coast, were due to fly to Victoria on Saturday afternoon.
Port Adelaide were already in Melbourne and are staying put before their clash with the Giants, which was originally meant to be at Metricon Stadium.
Brisbane Lions' match against Hawthorn in Launceston on Sunday has been given approval to go ahead as planned because the Lions flew out of Queensland earlier on Saturday.
The Lions are then set to stay on the road to take on Fremantle in Perth in round 21.
The round 20 reshuffle will almost certainly mean changes to the round 21 fixture.
With this week's game moved to Sunday, the Bombers are now unlikely to play the Western Bulldogs on Friday as scheduled as they would only get a five-day break.
Clubs are only allowed to have one five-day break in the season - as per the AFL Players' Association's agreement with the league - and Essendon had theirs between rounds three and four.
"We'll still go about our business on Monday, but beyond that day there's nothing set in stone," Bulldogs coach Luke Beveridge said.
"We'll wait to see what's organised and you'd imagine that the Friday night game will be off now."
West Coast's round 21 match against Melbourne in Perth could be moved from Saturday, August 7 to Monday, August 9 to allow the Demons to complete the required seven days quarantine before the match.
A VFL match between Gold Coast's reserves and Southport was called off midway through the first quarter on Saturday soon after the Queensland lockdown was announced.
Essendon's VFL game against Aspley and Brisbane's game against Sydney have been postponed.
SUNDAY'S ROUND 20 AFL FIXTURES (all times AEST)
Gold Coast vs Melbourne at Marvel Stadium, 12.10pm
Hawthorn vs Brisbane Lions at University of Tasmania Stadium, 2.10pm
Essendon vs Sydney at MCG, 3.10pm
Fremantle vs Richmond at Optus Stadium, 5.10pm
GWS vs Port Adelaide at Marvel Stadium, 6.10pm
Australian Associated Press