Tottenham manager Antonio Conte says that eight players and five members of staff have tested positive for Covid-19 at the club.
Spurs are scheduled to play Rennes in the Europa Conference League on Thursday and Uefa says "the match is due to take place as scheduled".
They then play Brighton on Sunday in a Premier League game which is believed to be under review.
"Every day, we are having more positives," said Conte.
"Everyone is a bit scared. People have families. Why [do] we have to take the risk? This is my question.
"Today, two positives.