The former world setter in tennis, the British Andy Murray, received a wildcard to the Australian Open.
But it is uncertain whether he can play this year's first grand slam tournament because he tested positive for covid-19.
According to the Scottish television company STV, Murray is feeling well and has isolated himself.
He still hopes to be able to take part in the Melbourne tournament which starts on 8 February.
All entrants must be quarantined in Melbourne for two weeks before the tournament.
Murray has fallen on the tennis rankings after a hip operation and is currently 123rd.