Australia coach Graham Arnold has tested positive for Covid-19 (AFP)
The Socceroos face Vietnam in Melbourne on Thursday with Arnold's deputy, former Manchester United assistant coach Rene Meulensteen, taking the reins.
Football Australia chief executive James Johnson said no one else in the set-up had failed a test so far.
"Graham and the Socceroos staff have sacrificed a lot over the past year to guide the team on a qualification campaign in the middle of a pandemic," Johnson said, with Australia forced to play all their home games so far overseas.
"So it is extremely unfortunate that on the eve of this important home qualifying match Graham has returned his first positive Covid result.
"We are pleased that our thorough protocols picked up this result early so that the risk of infection to players and staff leading into match week was controlled."
After falling out of the two automatic-qualifying positions in their Asian group with a loss and two draws in their past three games, the Socceroos cannot afford a slip-up against Vietnam.
Only the top two countries from each of the two groups will book an automatic ticket for the 2022 World Cup in Qatar, with the possibility of a fifth securing a spot through a play-off involving the third-placed teams.
Arnold said he had full faith in the players and his backroom staff.
"My staff and I have always planned that there could be a day that I might not be able to come to a match, so I believe with great planning and people in place, everything will run smoothly this week," he said.
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