Newcastle's Premier League match at Aston Villa on Friday has been postponed due to "a significant increase in Covid-19 cases at the Magpies' training centre", the Premier League has announced.
The game becomes the first Premier League match to be called off since the competition resumed following the March lockdown.
The north-east club shut their Benton complex on Monday due to a number of Covid-19 cases.
Magpies manager Steve Bruce had already cancelled training on Sunday after four players and a member of the backroom staff tested positive for the virus last week.
Bruce revealed after Friday night's 2-0 victory at Crystal Palace that three players had tested positive and were self-isolating.
The squad underwent further testing over the weekend and further individuals returned positive tests.
The first-team players have not trained since the win at Selhurst Park and the Premier League accepted that "the club are unable to train and adequately and safely prepare for their match on Friday" and that the match should therefore be rescheduled.
Premier League rules state that games should proceed as long as teams have a starting line-up plus three substitutes available, which can include players from the development squads, and that for a game to be postponed at least 14 players would have to be affected.
The fixture schedule is already a hectic one with many managers blaming a higher-than-usual rate of injuries on that.
The city of Newcastle itself will enter the tier three restriction band on Wednesday when the latest lockdown ends - the highest allocated by the UK Government.
Speaking after Friday’s game, Bruce said: "It has been a tough week.
"We sincerely hope (to avoid an outbreak). It is very difficult at the minute. We have three confirmed players and unfortunately a member of my staff.
"It is a concern and difficult to manage. We are trying our utmost to make sure we try and stay as safe as we can.
"Of course my concern is not just the welfare of the players, which is vitally important, but my members of staff too. We will do our best but it is difficult at the moment."