Australian spin bowler Adam Zampa is under an illness cloud for tonight's T20 World Cup clash against Sri Lanka after it emerged the star leg-spinner has COVID-19.

A team spokesperson confirmed Zampa recently returned a positive test but is only displaying minor symptoms. It puts him in considerable doubt for Tuesday evening's match at Perth Stadium, though the team insists he remains available for selection.

If picked, Zampa would have to travel to the match separately and his contact with other Australian players and support staff would be limited. But, before the tournament got underway, players who test positive for the virus are not prevented from competing at this year's World Cup.

Ireland's George Dockrell played against Sri Lanka on Sunday in Hobart despite the team identifying him as "potentially positive".

If the Aussies elect not to play Zampa, Ashton Agar shapes as the likely inclusion.

Agar has been a hard-luck story of the world champions' T20 side after their move to fielding just four specialist bowlers.