Newcastle United's training ground remained closed for a second successive day on Tuesday in an attempt to deal with an outbreak of coronavirus.
Manager Steve Bruce said on Friday that three players and one member of staff had tested positive and on Monday the training ground was shut.
After a round of testing on Sunday, there have been further cases and players have remained at home.
The Magpies are due to play Aston Villa in the Premier League on Friday.
It is not clear if the team will return to their training base on Wednesday.