Newcastle United's visit to Southampton has become the latest Premier League match to be postponed due to the effect of COVID-19 on playing staffs.
Friday's decision prompted Southampton to ask the Premier League for clarity over procedures.
Saints are said to be frustrated by Newcastle's inability to field a team, having been forced to use fringe and youth-team players in matches themselves over the last year, notably when they were thrashed 9-0 at Manchester United in February.
Sunday's fixture was called off as Newcastle said a combination of COVID-19 cases and injuries in the meant they were unable to raise the minimum requirement of 14 players including a goalkeeper.
The Premier League accepted this.
The game at St Mary's is the second postponement of the weekend with the New Year's Day match between Leicester and Norwich already off.
It brings to 18 the number of Premier League matches postponed amid the recent surge in coronavirus cases.
Jurgen Klopp said he did not expect Liverpool's match at Chelsea on Sunday to add to the list despite the club recording positive tests in another three players.
"It's not so cool at the moment," the manager said.
He added: "We never had an outbreak where 10-15 players had it. For us, it's more every day another one (tests positive)... it feels like a lottery in the morning. It's day by day another case. We don't know how it will look in a few hours."
His Crystal Palace counterpart Patrick Vieira could return to the touchline for Saturday's visit of West Ham on Saturday after missing two matches following a positive test.
Those teams who are back in action are unsure how the unexpected break will affect them.
Wolves have not played since December 19 after having two matches postponed, the second - at Arsenal on Tuesday - at their own behest. Manager Bruno Lage said: "Today I was talking with a player and I asked 'are you ready to play?'
"He said: 'I really don't know'. After 10 days without playing and training you are slow to take the right decisions."
Across the English Channel the French league have postponed the game between Angers and Saint-Etienne on January 9 because of a high number of coronavirus cases in the Angers squad.
The Africa Cup of Nations has already been affected, more than a week before it starts. Hosts Cameroon, who launch the tournament on January 9 against Burkina Faso, has had four players in their squad test positive.
There are also seven cases in the Cape Verde Island squad with Ivory Coast, Algeria and Morocco also affected.
It is not just players and coaches being ruled out by the pandemic. In the NBA three referees were been called up from the G League, a development league, on Friday to replace officials ruled out by COVID protocols.
None of the three had even worked an NBA pre-season game but with around a third of the league's referees unavailable the NBA had little choice.
Los Angeles Clippers head coach Tyronn Lue was placed into the NBA's health and safety protocol on Friday with assistant coach Brian Shaw set to lead the team into a road game against the Toronto Raptors.
Multiple other coaches still are out because of COVID-19 concerns, include the Philadelphia 76ers' Doc Rivers, the Denver Nuggets' Michael Malone, the Phoenix Suns' Monty Williams, the Chicago Bulls' Billy Donovan, the Portland Trail Blazers' Chauncey Billups and the Oklahoma City Thunder's Mark Daigneault.