Tyrone man Conor McKenna is undergoing fresh tests for Covid-19 to discount the possibility of a false positive after his failed test forced the cancellation of an AFL game at the weekend and a change in regulations for players.

The Eglish native was the first player to test positive for coronavirus since Aussie Rules returned last week, which prompted the sport's governing body to postpone the scheduled game between McKenna's Essendon and Melbourne on Sunday, and tell the cub's staff and players to isolate.

Australian media reported that officials were retesting McKenna today after he tested negative on Wednesday, returned a 'low level irregular result' after training on Friday and then tested positive on Saturday. He is asymptomatic.

The former Red Hand minor footballer could also face suspension after reportedly viewing a house and visiting friends in contravention of league guidelines on social distancing.

Essendon have been told they will have to play Saturday's game against Carlton as scheduled even if McKenna and his contact training group of eight team-mates are still in isolation.

As a result of the positive test, the AFL today also announced they had also changed their rules around contact training, restricting full-team contact sessions to one per month.

Full-team non-contact training will be allowed once per week but otherwise players must be confined to pods of eight/nine.

Players and staff have also been told not to visit other houses or have visitors in their house from 48 hours before to their weekly pre-match test.

McKenna (24) had returned to Ireland after the AFL season shut down in March but he went back to Australia last month and underwent a 14-day quarantine period.

He had tested negative five times before the latest two tests.

The AFL resumed its season last week after nearly a three-month shutdown.