COVID-19 has forced plenty of fixtures to be postponed this season, but Manchester United's meeting with Liverpool was cancelled for a whole different reason.
Thousands of fans descended on Old Trafford in the build-up to the game to protest against the owners of the club, the Glazer family, and things spiralled out of control to the point that the game could not be played safely.
With just a few weeks left in the season, there isn't a lot of time spare to fit this game in, but the Premier League are going to have to figure out a way to do it.
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The Premier League have condemned the Manchester United fan protest that led to their game against Liverpool being postponed on Sunday.
The Manchester United lineup that should start against Aston Villa in the Premier League
Why was Man Utd vs Liverpool postponed?
The simple answer to this is that the protests escalated to such an extent that authorities decided it was no longer safe for the players or anyone else involved to play the game.
On top of the obvious dangers relating to COVID-19 that come from thousands of strangers grouped together and touching everything inside and outside the stadium, there was also a danger of violence as clashes between supporters and police turned pretty ugly.
Remaining Man Utd fixtures
Roma vs Man Utd (May 6)
Aston Villa vs Man Utd (May 9)
Man Utd vs Leicester (May 12)
Man Utd vs Fulham (May 19)
Wolves vs Man Utd (May 23)
With United pushing for Europa League glory, their ending is a little hectic. On top of this Liverpool game, there are four other domestic ties and the European semi-final to navigate, and barring a miracle of Corner Taken Quickly Origi-esque proportions, they'll also be in the Europa League final on May 26.
As you can see, there's a gap on the weekend of May 15, but that doesn't work for Liverpool...
Remaining Liverpool fixtures
Liverpool vs Southampton (May 8)
West Brom vs Liverpool (May 16)
Burnley vs Liverpool (May 19)
Liverpool vs Crystal Palace (May 23)
Jurgen Klopp's men are scheduled to face West Brom on May 16, which means there is no logical time for this fixture to be rearranged. The Premier League bigwigs are going to have to get creative.
When could Man Utd vs Liverpool be played?
With United the busier of the two teams, their schedule will have to take priority here. They have just one vacant slot in their calendar, so it wouldn't be a surprise to see the Premier League try and fit this game in on the weekend of May 15.
For that to work, however, Liverpool's game with West Brom would have to be moved to their vacant spot on May 12. It might not be a popular decision for the Baggies, who will be at the Emirates to face Arsenal three days earlier, but there aren't many options.
Failing that, the idea of rejigging some midweek fixtures to make both sides play three times a week on a Tuesday-Thursday-Sunday split could be considered, but given players are already being pushed to their physical limits, that would hardly be ideal.