Steven Gerrard is worried, and so are his players. The Aston Villa manager is taking almost hourly bulletins on how badly his squad has been affected by positive COVID-19 cases and whether he will have enough players — 13 outfield players and a goalkeeper — to meet the minimum requirement to fulfil a Premier League fixture.

Villa were forced to postpone last Saturday's game against Burnley just over two hours before kick-off because of a COVID outbreak at the club, and they may be severely depleted against Chelsea on Sunday, but the impact goes behind simply having a fixture called off. Footballers are just as concerned about the virus and the vaccination process, as well as the long-term effects of both, as everyone else.

"We had a situation at the weekend where one of the players was reluctant to get out of his car because he had some symptoms and he's got a young family, and you can totally understand his view in his situation," Gerrard said at a news conference this week. "This is a guy who's got a young family, it is Christmastime, and that's the situation everyone is in. No one wants to get this virus. Everyone wants to protect their own families.

"Thankfully he was tested after and he didn't have a situation, but that player would not have been available for me on the day, and these are the little situations that people don't see. We've got a major responsibility to listen to the players and deal with every situation as it comes your way."

The Premier League is experiencing a COVID-19 crisis. Six of 10 fixtures were postponed last weekend due to outbreaks at a host of clubs, three games slated for Dec. 26 have already been called off, a record high of 90 positive results among players and staff were recorded during the most recent testing period (the previous high was 42) and, in official data released by the league earlier this week, it was revealed that only 77% of players among the 20 clubs have been fully vaccinated.

Perhaps the starkest statistic of all was that 16% of Premier League players have not received a single dose of the vaccine. The most recently released vaccination figures from other major European leagues show the Premier League to be lagging some distance behind their competitors. In Italy, Serie A has recorded 98% of players being fully vaccinated, Ligue 1 have reported 95% in France, while Germany's Bundesliga and Spain's LaLiga both have 92% of players fully vaccinated.