It's impossible to say when the transfer window will open this summer. 

Players' comings and goings are the last thing on anyone's mind right now, but it's safe to say that the landscape will look entirely different when football does return. 

The coronavirus pandemic is having an unprecedented impact on every club's finances and inevitably, the values of individual players are also taking a nosedive. 

The Mirror have summarised Transfermarkt's recent valuations, taking into account how the COVID-19 outbreak has affected the stars of the Premier League's big six. 

The results are telling. All six sides have seen their squad values slump by as much as 19% and that could have huge ramifications, with the ripples being felt across the European market. 

Manchester City's squad has felt the biggest material impact with a knock of 19.7% in value since mid-March. 

Yet they're far from the only club who must be weighing up how they would be affected if they were to cash in on some of their biggest names in the coming months. 

Liverpool

Mohamed Salah and Sadio Mane - £135m down to £108m. 

Trent Alexander-Arnold - £99m down to £89.1m. 

Virgil van Dijk - £90m down to £72m.

Alisson Becker - £81m down to £64.8m.

Manchester City

Raheem Sterling - £144m down to £115.2m

Kevin De Bruyne - £135m down to £108m. 

Leroy Sane and Bernardo Silva - £90m down to £72m.

Rodri - £72m down to £57.6m.

Chelsea

N'Golo Kante - £90m down to £72m. 

Christian Pulisic - £54m to £48.6m. 

Jorginho - £58.5m to £46.8m.

Mason Mount - £40.5m down to £36.45m.

Antonio Rudiger - £45m down to £36m. 

Manchester United

Paul Pogba - £90m down to £72m. 

Marcus Rashford - £72m down to £57.6m.

Harry Maguire - £63m down to £50.4m. 

Anthony Martial -  £53m down to £43.2m.

Bruno Fernandes - £53m down to £43.2m.

Tottenham Hotspur 

Harry Kane - £135m down to £108m. 

Dele Alli and Son Heung-min - £72m down to £57.6m.

Tanguy Ndombele - £58.5m down to £46.8m. 

Davinson Sanchez - £54m down to £43.2m. 

Arsenal 

Pierre-Emerick Aubameyang - £63m down to £50.4m. 

Nicolas Pepe - £58.5m down to £46.8m. 

Alexandre Lacazette -  £54m down to £43.2m. 

Matteo Guendouzi - £40.5m down to £36.45m

Lucas Torreira - £40.5m down to £32.4m. 

How many of those players will actually be on the move? 

Liverpool probably don't have too many concerns, but Arsenal will be sweating on Aubameyang even more than they were before. 

The striker's contract expires next summer and rather than risk losing him for free, it must be crossing the Gunners' collective mind to bring in some income from him - but it's suddenly looking like a much smaller fee on the horizon. 

You might imagine Manchester United are scratching their heads with the same calculations regarding Pogba, who is reportedly still attracting interest from Real Madrid. 

The real takeaway is that the business of football may take years for recover.

The transfer market as we know it may have changed forever.