SUNDAY'S Essendon-Melbourne match has been postponed after Bomber Conor McKenna tested positive for COVID-19. 

AFL chief executive Gillon McLachlan confirmed the decision a short time ago to clubs and then in a media conference at the MCG.  

All other round three matches, as well as next week's round four games, will be played, albeit with the potential of altered start times.

Revised Sunday fixture
Gold Coast v Adelaide will move from 1:05pm AEST to 3:05pm AEST 
Fremantle v Port Adelaide will move from 6:10pm AEST to 8.10pm AEST

McKenna returned from Ireland last month and self-isolated for two weeks as per national protocols.

He then returned to the Bombers for full training, was named to play his first game of 2020 on Sunday and was with teammates as recently as Friday morning. 

Importantly, McKenna did not train on Saturday morning and displayed no symptoms that he might have the coronavirus.

He had tested negative five times, including as recently as Wednesday, before returning a low-level reading on Friday that was originally classified as an irregularity.

All other Essendon players and football department staff tested negative on Friday.

McLachlan said that result had given the AFL "a lot of comfort".

FULL STATEMENT Gill explains decision

A subsequent test on Saturday morning returned a positive reading by the afternoon for COVID-19.

All players are required to complete a COVID-19 test 24 hours out from each main training session and match. 

McLachlan is confident McKenna contracted the virus in Melbourne this week but said he would leave the confirmation of that to the Department of Health and Human Services.

The DHS will now go through the process of identifying all of the close contacts with McKenna and placing them in isolation. All training sessions are videoed for this purpose.

"I'm clearly disappointed. I'm disappointed for Conor (and) I'm disappointed for Essendon and their playing cohort," McLachlan told reporters.

"But I think in the end this was always a possibility, whether it was likely or not.

"I'm pleased we had a whole series of procedures put in place quite quickly. We've got an ability to rejig our fixture and work through this, so I feel we are well prepared.

"Clearly, we're disappointed for the player, the team and the competition but we understand this is a possibility and we will work through that."

McKenna will continue to be tested until he returns a negative reading.

Essendon players and staff are due to be tested again on Tuesday, a date McLachlan confirmed would not be brought forward.

He also said the club's headquarters will be shut down for a period of time.

"DHS will make that decision with our infectious diseases and medical team but I think it's fairly certain the club will be thoroughly cleaned over the next 24-48 hours and shut down for that period," he said.

The AFL this week eased the strict protocols players and staff must abide by, including allowing them to engage in recreational activities, and McLachlan said this would be reviewed.  

"I'd say to everyone this is an amazing reminder about why we have protocols in place that are tougher than the community standard on our players and footy department officials," he said.