It's a lock (if there can be such a thing in a COVID-ruled AFL fixture): Port Adelaide will play top-eight rival Greater Western Sydney in Melbourne on Sunday evening.

The round 20 fixture will be at Marvel Stadium - rather than on the Gold Coast or the original setting of Canberra - and will mark Port Adelaide's third consecutive match at the west Docklands arena.

Start time will be 5.40pm (SA time), three hours later than the first bounce was planned at Metricon Stadium on the Gold Coast.

These changes were forced on the AFL on Saturday morning by the three-day lockdown called in Queensland where Greater Western Sydney has been based since the COVID crisis began in Sydney earlier this month.

For Port Adelaide, the consequences of yet another late change to the AFL fixture are -

NO early Sunday morning travel to Queensland with the team able to repeat last week's routine for the "home" game against Collingwood while hubbed in Melbourne,

RETURN flight to Adelaide on Monday morning,

ISOLATION for probably 48 hours in Adelaide on return,

ACCESS to Alberton Oval for training - a necessity not granted by SA Health last week during Adelaide's third lockdown, forcing Port Adelaide to move to Melbourne

SHOWDOWN L to go ahead at Adelaide Oval next weekend.

Port Adelaide football chief Chris Davies detailed these expectations - all vulnerable to change - after the team completed its training program with a captain's run at Punt Road at Richmond on Saturday.

"It was an interesting morning," Davies said. "We had started our meetings with the coaches and halfway through that we got the word that Queensland was going into lockdown.

"Things quickly changed. First, the game was postponed ... and working out if the game could be played this weekend.

"Now, the game gets played at Marvel Stadium. And we won't get home until - most likely - Monday morning.

"The first thing we will have to do when we get home is spend a period of time (48 hours) in our houses, isolating and only coming out to the club for rehab and training. SA Health will then look at what we can do in the community.

"First and foremost for us is to make sure that at the very least we can leave our houses to go to training as any professional sporting team needs to. That is the reason why we let Adelaide (last Tuesday after SA Health banned training sessions for all sports)."

Port Adelaide's return to Alberton was confirmed on Friday by the AFL and is not expected to change by playing Greater Western Sydney which has been in its own bubble in south-east Queensland.

Port Adelaide players and staff will be subjected to more COVID tests to reassure SA Health.

"We are aware of the exemption we have to return," Davies said. "GWS have been isolated. The chance of the GWS team being in an exposure area will be minimal.

"So far, it is confirmed we will be able to isolate and leave home to go to training."

Port Adelaide has a less demanding game-day program that the one planned for a trip to the Gold Coast on Sunday morning.

"To not have to get up (before dawn for a charter flight to Coolangatta) to fly in on the day of the game is a good outcome," Davies said. "We are the club that has done (same-day match travel) the most in the competition. We think we would have been able to do that (on Sunday) ...

"Our staff have done an amazing job (with the Melbourne hub) to make sure the players are well prepared. Our players have shown incredible resilience. The past week and a half has been crazy for us - it has been a challenge. 

"Today was interesting and I got to a point this morning where you stop speculating on what could happen and you wait for the AFL which has done a fantastic job to tell you what will happen.

"We were training by the time the AFL could confirm to us what they thought was most likely to occur. Things have been relatively smooth from there.

"The challenge for every club is to remain flexible. We have done it in a manner that has achieved results - and we have not whinged. We can be proud of this when we look back, but we also know our great challenge is to continue to finish the minor round in a position that augurs well for the finals series."

Port Adelaide has confirmed one change for the match. Specialist forward Orazio Fantasia returns for his first AFL match since he had corrective surgery to a knee during the mid-season bye eight weeks ago.

The Essendon recruit replaces Boyd Woodcock and Sam Mayes in the 23 who overcame Collingwood at the Docklands in Friday Night Football when former captain Travis Boak played his 300th AFL match. Boak will become Port Adelaide's most-capped AFL player with his 301st game (taking this record from 2004 premiership midfielder Kane Cornes) and young forward Todd Marshall will reach his 50th AFL milestone.

"Fantasia will play which is a great thing for us," Davies said. "He adds a different dimension to the group. It is a pretty significant step (in the preparation for next month's finals).

"We gained (Connor Rozee, Xavier Duursma and Zak Butters from injury) last week and we will have to integrate them into the way our team plays."

Port Adelaide enters the last four weeks of the home-and-away series with Steven Motlop (ankle) and Robbie Gray (knee) to come off the injury list before finals.

"To be in the position we are in (fourth, 13-5) with the opportunity to be better has us pretty well placed," Davies said. "Time will tell. But we need to get those players back in and playing well because we know we need those players when the whips are cracking."