English football could be braced for more disruption after a host of further coronavirus outbreaks on Monday.
Manchester City's Premier League game at Everton was postponed just four hours before kick-off after a "number of positive cases" at City, which came three days after Kyle Walker and Gabriel Jesus were among four individuals to return positive tests.
League One clubs Doncaster and Rochdale have seen their next three and two games respectively wiped out by Covid-19, with League Two Morecambe also announcing their next two games were off.
As cases continue to surge across the country, the calendar could be further hit with games coming thick and fast.
Everton said in a statement on Monday night that the postponement was regrettable and that they would ask the Premier League for a full explanation of the decision-making process.
The statement read: "Everton Football Club regret the postponement of tonight's match against Manchester City – not only for the 2,000 fans who would have been attending, but for supporters on Merseyside and across the world.
"Our players were prepared for the game, as were both the team staff and everyone at Goodison. Matchday is the most important date in our calendar. And this was a big one.
"Whilst Everton will always have public safety uppermost, we will be requesting full disclosure of all the information that Manchester City provided to the Premier League so the club can be clear on why this decision was taken."
The Premier League, in agreeing to the postponement, insisted the health of players and staff was paramount.
"The board agreed to rearrange the game as a precaution, and further testing will now take place (on Tuesday)," said a statement.
"The decision has been taken with the health of players and staff the priority."
The fixture was the second Premier League game to be called off this season due to positive tests for coronavirus – Aston Villa and Newcastle having been the first on December 4 due to cases within the Magpies' camp.
The Premier League statement added: "The Premier League continues to have full confidence in its protocols and rules, and the way in which all clubs are implementing them.
"The League wishes those with Covid-19 a safe and speedy recovery and will rearrange the postponed fixture against Everton in due course."
City's training ground has been closed for the foreseeable future, with the rest of the squad having to undergo extensive further testing before any potential return can be considered.
The club's next match is due to be at Chelsea on Sunday, which is then followed by their Carabao Cup semi-final against derby rivals Manchester United at Old Trafford on January 6.
Chelsea manager Frank Lampard said he was in the dark over his side's next two games – the meeting with City and their FA Cup third-round tie with Morecambe.
"It is a key time and a tough time," Lampard said after Chelsea's 1-1 home draw with Aston Villa. "I think we felt that coming as tier four came in with the surge.
"We have to get safety as paramount. I believe that's why the game has been called off, because of the spread in the squad for Man City. From our point of view, I will find out in the next day or two because it has to be safe for the two teams: if not the game won't go ahead.
"I think the Premier League will direct us on that but yes, it is a tough time. I am not surprised because the public and with how Covid is in the UK is difficult for everybody.
"Football isn't different all the time so we will have to see what the PL come up with but safety is paramount."
National League games at Barnet, Boreham Wood, Chesterfield, Dagenham and Redbridge and Sutton were postponed on Monday after positive tests were returned at various clubs.