Carlton are preparing as if next weekend’s AFL match against Essendon will go ahead but are uncertain it will, after Conor McKenna’s positive COVID-19 test.

The Bombers have been sent into isolation and their planned clash with Melbourne in round three, which was scheduled for Sunday at the MCG, has been postponed indefinitely.

McKenna’s positive test is a massive hurdle for the AFL as it attempts to plot a course forward to complete a reduced 153-game season, including finals.

The Bombers-Blues clash set for Saturday night at the MCG is in doubt as Essendon players and staff await further coronavirus testing and results.

Carlton forward Levi Casboult said the Blues would prepare as normal in the hope the round four fixture goes ahead as scheduled.

“You plan to play until you’re told otherwise; otherwise you’re on the back foot,” Casboult told the Sunday Footy Show.

“If we wait until Monday, there’s two days of recovery that you might not have done or whatever it is. We’re planning to play.”

AFL chief executive Gillon McLachlan on Saturday said the AFL season would continue but cannot yet guarantee a return date for Essendon.

The AFL and health department are investigating McKenna’s movements in recent days to determine how and when the Irish defender contracted COVID-19.

McKenna returned from Ireland last month but officials believe he contracted the virus in Melbourne.

The 24-year-old had recorded seven negative tests before recording a “low level irregularity” after Friday’s training session.

He was retested on Saturday morning and returned a positive result.