Premier League clubs must set an example in adhering to coronavirus protocols or risk sanctions, the league's chief executive has warned.
The English top-flight sent out new directives last week including demands that players tone down celebrations such as hugging after goals and avoid handshakes and swapping shirts.
Premier League chief executive Richard Masters followed that up with a letter to clubs on Tuesday, writing: "We are fortunate to be able to continue to play and bring our competition to fans at home and around the world.
"This brings justified additional scrutiny and the Premier League must take the lead in setting the right example to follow."
But despite the message, Manchester United players joyously celebrated Paul Pogba's goal in their 1-0 win over Burnley on Tuesday, which sent them three points clear at the top of the table.
United manager Ole Gunnar Solskjaer said afterwards: "We'll do our best to keep with the guidelines because we all want football to carry on safely."
English Football League (EFL) chief executive Trevor Birch has said the game will come under extreme government pressure to stop if clubs "continue to flout the rules" on limiting the spread of coronavirus.
And Britain's Press Association news agency reported on Wednesday that match officials would warn captains in a bid to stamp out goal celebrations.
Britain is battling a new, more transmissible strain of the virus that is spreading rapidly -- authorities on Wednesday announced another 1,564 virus fatalities, a daily record
The Premier League has so far been forced to postpone far fewer matches than the EFL due to coronavirus infections. Only a handful of games have been called off compared to dozens outside the top flight.
However, there are doubts over Aston Villa's game with Everton this weekend, which has already been moved to Sunday from the original Saturday slot.
Villa were unable to fulfil Wednesday's league clash with Tottenham because several of their players and staff tested positive for coronavirus last week.
Tottenham instead played Fulham at short notice.
Masters admitted more postponements could be on the cards.
"It is already clear that we must do all we can to efficiently utilise all available calendar slots," he said, warning that clubs' requests for postponements would often be "at short notice".
It was announced later Wednesday that Southampton's postponed FA Cup third-round tie against Shrewsbury had been rescheduled for January 19, with next week's Premier League fixture at Leeds called off.
The cup game had been set for January 9, but was postponed because of a coronavirus outbreak at the League One club.
Elsewhere, Sheffield Wednesday's next two Championship games have been suspended after a Covid-19 outbreak.