Tottenham’s Europa Conference League match against Rennes on Thursday is off after eight players and five members of staff tested positive for Covid-19 at the London club.
Their match against Brighton on Sunday in the Premier League is believed to be under review.
Spurs said they closed their first-team training centre on Wednesday.
“Discussions are ongoing with Uefa. We shall provide a further update on this fixture in due course,” the club said.
Speaking earlier on Wednesday, Spurs manager Antonio Conte said:
“Now, for sure, we are a bit scared because tomorrow we don’t know what happens.
“Every day, we are having more positives. This is not a good situation.”