How has Brexit affected the January transfer window?

"Brexit means Brexit" apparently, but what does that mean for possibly the most globalised organisation in Britain, the Premier League? With the details of how Brexit will actually work still locked away inside the minds of the Conservative government and subject to negotiations with the European Union, it is hard to make specific claims about how England's top flight will be affected.

But, given that immigration is a key pillar of Prime Minister Theresa May's policies, and that the EU has already stated that free movement is a central tenet of its regulations, it is highly unlikely that football could run without change. At the moment any European player is free to be signed by an English club. Non-Europeans, however, have to pass a set of criteria in order to qualify for a work visa.

The Football Associations rules currently state that non-European players must have played a certain percentage of competitive games for their national team in the period leading up to the proposed transfer to the Premier League. If the player is from one of the world's top ten footballing nations, he must have appeared in 30% of international fixtures in the previous two years. A sliding scale means that players from nations outside the world's top 30 must have played 75% of their country's competitive matches.

Assuming that Britain were to enforce similar rules on European footballers post-Brexit, The Guardian calculated (before the Referendum) that two-thirds of European players in England would not automatically qualify to play in the Premier League. Top flight clubs have, however, had much success arguing for exceptions. Would players who did not fit the criteria still be allowed to play in England in future?

In a bid to gain some clarity into how the teams you support might be affected by Britain leaving the European Union, we have looked at the latest batch of transfers during the January window and attempted to extrapolate what we might learn, including whether each player would actually be able to make such a move from 2019, when, according to the Article 50 timeline, Britain would no longer be a part of the Union.

Arsenal

Cohen Bramall, 20, defender, £40,000, Hednesford Town, born Crewe

Post-Brexit expect to see more youngsters England's lower leagues becoming targets for the big clubs.

Bournemouth

Aaron Ramsdale, 18, goalkeeper, undisclosed fee from Sheffield United, born Stoke-on-Trent

As with Arsenal, Premier League clubs will be more likely to scour the lower leagues for potential English talent.

Burnley

Ashley Westwood, 26, midfielder, £5m, Aston Villa, born Nantwich

Robbie Brady, 25, winger, £13m, Norwich, born Dublin, 31 caps for the Republic of Ireland

Joey Barton, 34, midfielder, unattached (Glasgow Rangers), born Huyton, 1 England cap

From 2019, expect to see more experienced/over-the-hill English players like Barton being brought in to 'do a job'. As a regular international, Brady would probably pass whatever hurdles the FA/Premier League placed on foreign players, but he would be classed as an overseas player coming from Europe. This would be signficant if limits were placed on the number of overseas players allowed per-team post-Brexit.

Chelsea

Kyle Jameson, 18, defender, unsigned (Southport), born Manchester

Chelsea's departures were packed full of sales to China and loanees to clubs across Europe including the lower leagues of England. Would European clubs still be allowed to sign unproven youngsters from English teams on loan deals? Unlikely given the likelihood that the EU would place more stringent rules on British citizens living and working in Europe.

Crystal Palace

Jeff Schlupp, 24, winger, £12m, Leicester City, born Hamburg, Germany, 13 caps for Ghana

Patrick van Aanholt, 26, defender, £14m, Sunderland, born Netherlands, six caps

Luka Milivojevic, 25, midfielder, £12m, Olympiakos, born Serbia, 19 caps

Mamadou Sakho, 26, defender, loan, Liverpool, born Paris, 28 caps

While Sam Allardyce's pre-deadline signings are internationals, it is unlikely that all – or indeed any – would automatically qualify for a visa to play football in England given the rules on making regular and recent international appearances for their country. How many would be given exemptions?

Everton

Ademola Lookman, 19, forward, £7m, Charlton, born London

Morgan Schneiderlin, 27, midfielder, £20m, Everton, born France, 15 caps

Anton Donkor, 19, forward, loan, Wolfsburg, born Germany, not yet an international

It is hard to see an untried German youngster such as Donkor being allowed a visa post-Brexit

Hull City

Markus Henriksen, 24, midfielder, loan, AZ Alkmaar, born Norway, 31 caps

Oumar Niasse, 26, forward, loan, Everton, born Senegal, 8 caps

Evandro, 30, midfielder, Porto, born Brazil, no senior caps

Omar Elabdellaoui, 25, defender, Olympiacos, born Norway, 23 caps

Lazar Markovic, 22, winger, Liverpool, born Serbia, 22 caps

Andrea Ranocchia, 28, defender, Inter, born Italy, 21 caps

Alfred N'Diaye, 26, midfielder, loan, Villareal, born Paris, 8 caps for Senegal

Kamil Grosicki, 28, winger, £8m, Rennes, born Poland, 48 caps

Few of Hull's signings would pass the most stringent regulations for a football visa. How many would be granted exemptions in a post-Brexit world? Would football be allowed to openly flout the restrictions of movement imposed upon other sections of society?

Leicester City

Wilfred Ndidi, 20, midfielder, £15m, Genk, born Nigeria, 6 caps

Molla Wague, 25, defender, loan, Udinese, born France, 20 caps for Mali

Liverpool/Manchester City/Manchester United

No signings

Middlesbrough

Mikael Soisalo, 18, winger, undisclosed, Ilves, born Finland, no senior caps

Rudy Gestede, 28, forward, £6m, Aston Villa, born France, 11 caps for Benin

Patrick Bamford, 23, midfield, £5m, Chelsea, born Grantham, no senior England caps

Adlene Guedioura, 31, midfield, £4m, Watford, born France, 32 caps for Algeria

Again, it is hard to see many of these players automatically passing the FA's guidelines on footballing status as regular internationals, so how many of them would be waived?

Southampton

Mouez Hassen, 23, goalkeeper, loan, Nice, France, no senior caps

Manolo Gabbiadini, 25, forward, £17m, Napoli, Italy, 6 caps

Without free movement within the European Union, these signings would fail the wider international visa rules tests. Would they be allowed visas anyway? Would European clubs allow loan deals to England if such deals were not allowed in the opposite direction?

Stoke City

Lee Grant, 34, goalkeeper, £1m, Derby County, Hemel Hempstead, no caps

Saido Berahino, 23, forward, £15m, WBA, Burundi, no caps

Although Berahino was born in Burundi he is qualified to play for England after arriving here as a refugee at just 10-years-old. Would such a journey be allowed in a post-Brexit Britain that is tightening up on immigration?

Sunderland

Joleon Lescott, 34, defender, unsigned, born Birmingham, 26 caps

Darron Gibson, 29, midfielder, Everton, born Derry, 27 caps for Republic of Ireland

Bryan Oviedo, 26, defender, £7m, Everton, born Costa Rica, 31 caps

Although born in Northern Ireland, Gibson chose to play for the Republic and Fifa supported this because he is considered to be an Irish citizen. Post-Brexit, with borders likely to be re-established between north and south, would this still be allowed?

Swansea City

Luciano Narsingh, 26, winger, £4m, PSV, born Netherlands, 16 caps

Martin Olsson, 28, defender, £4m, Norwich, born Sweden, 40 caps

Tom Carroll, 24, midfielder, £4m, Spurs, born Watford, no senior caps

Jordan Ayew, 25, forward, £5m, Aston Villa, born France, 46 caps for Ghana

Would Luciano Narsingh, a player on the fringes of the Netherlands national side be granted a visa to play in the Premier League using the international guidelines?

Tottenham Hotspur

No signings

Watford

Mauro Zarate, 29, forward, £1.6m, Fiorentina, born Argentina, no senior caps

Tom Cleverley, 27, midfield, loan, Everton, born Basingstoke, 13 caps

M'Baye Niang, 22, winger, loan, AC Milan, born France, no senior caps

Zarate and Niang have no senior international caps but have been given visa waivers in the period when the Premier League has been allowed to import just about whichever players it wants.

West Bromwich Albion

Jake Livermore, 27, midfielder, £10m, Hull, born Enfield, no caps

Marc Wilson, 29, defender, loan, Bournemouth, born Northern Ireland, 25 caps for the Republic of Ireland

Wilson is another who falls into the category of players who have been allowed to choose between Northern Ireland and the Republic. With one of these inside Europe and other outside, it is unclear how future nationality will be decided.

West Ham United

Jose Fonte, 23, defender, £8m, Southampton, born Portugal, 20 caps

Nathan Holland, 18, midfield, free, Everton, born Manchester, no caps

Robert Snodgrass, 29, winger, £10m, Hull, born Glasgow, 21 caps for Scotland

Before the advent of the Premier League, England's biggest clubs often featured large numbers of Scottish, Welsh and Irish players (think of Liverpool in the 70s and 80s). Would Brexit signal a return to this pattern? Would the Premier League be so internationally popular if it featured fewer players from around the globe? Would the Premier League, as a high-profile British institution, be allowed to present an unchanged mixture of nationalities when the government has declared a clampdown on immigration?

At this stage, of course, we are hypothesising. The Premier League – and its important allies such as Rupert Murdoch's Sky TV – is one of Britain's most recognisable global success stories. But its international growth has been forged with an influx of overseas players. What would be the new rules before European and international players are eligible to appear in the English league? Would visa rules be applied more stringently? Would standards fall if the influx slowed? And what would the fans prefer?