Al Ahly's preparations for the inaugural edition of the Egyptian League Cup were rocked on Sunday after Tau was confirmed as one of five players who had tested positive for the coronavirus.
The former Mamelodi Sundowns star has since been excluded from the club's matchday squad ahead of Thursday's tournament opener against El Gouna and will undergo further tests during the day.
"Percy Tau, Al Ahly forward, will undergo a Covid-19 test on Thursday to check on his condition," the club said in an official statement.
"Ahmed Abu Abla, the team’s doctor, stated that Tau’s condition is stable and he will undergo a test on Thursday to determine his returning date to the team’s full training..."
While the 27-year-old's prognosis appears positive, his absence remains a blow for coach Pitso Mosimane who has heavily relied on the forward's attacking output this season.
Tau has been one of the star performers for the Red Devils since joining the club from Brighton & Hove Albion at the start of the campaign and has already scored five goals in eight appearances since his move to Egypt.