Newcastle United's players have been told to stay away from their training ground following an outbreak of COVID-19 in the squad.
Three of their squad missed last Friday's Premier League win over Crystal Palace after testing positive for coronavirus, with a further two cases detected on Sunday.
The club carried out another round of testing on Sunday and there are more tests scheduled to take place on Wednesday.
Magpies boss Steve Bruce was forced to give the squad the weekend off and no training took place on Monday or Tuesday.
Newcastle say they will monitor the situation on a day-to-day basis but it means Friday night's game away to Aston Villa is in doubt.
The game at Villa Park is due to go ahead as things stand but should Newcastle wish to have the game postponed, the club would have to appeal to the Premier League board.
The Premier League has previously stated that it will review each case individually but it was previously stated that matches should go ahead if teams have a starting 11 and three substitutes.
No Premier League match has been postponed since it resumed in mid-June for the end of last season.
It is still not clear when the original outbreak happened at the training ground, and whether it was a result of players being away on international duty.
Newcastle are 13th in the Premier League with four wins from their opening 10 top-flight games and have only suffered one defeat away from home in the league this season.