West Brom boss Sam Allardyce has revealed new Brexit regulations have already harmed his transfer plans.
The Baggies have been forced to pull out of three deals after it became clear players would not qualify for a work permit.
Points will be awarded for senior and youth international appearances, club appearances and the pedigree of the selling club after the UK completed its split from the European Union on New Year's Eve.
Albion are second bottom of the Premier League after Saturday's 4-0 defeat to Arsenal and Allardyce is finding his search for January reinforcements hampered by new red tape.
He said: "I have found three players already who were capable of coming here and they're not allowed. It's a shame.
"Due to the new regulations in terms of the permit they were unable to come to this country, whereas (previously) they would have done. I have to look at that and think 'can he qualify?'
"That has made life a bit more difficult. It's not so much the pandemic, it's the change of rules because of the Brexit deal.
"We will do what we can and finding a player in this pandemic is going to be the hardest window I have ever worked in.
"No disrespect to my players here because they are all working as hard as they can but I do have to find better to lift the squad.
"Whatever player comes in they have to be better than what we have and capable of going into the team almost immediately."
Albion suffered another heavy home defeat on Saturday to the Gunners, coming after they were thumped 5-0 by Leeds.
Alexandre Lacazette scored a second-half double after Kieran Tierney and Bukayo Saka gave the visitors a comfortable lead at the break.
The Gunners climbed to 11th after a third straight win and they are three points off the top six, having played a game more.
Pierre-Emerick Aubameyang drew a blank and has netted just once in his last eight games but boss Mikel Arteta is pleased his players are sharing the goals.
He said: "I keep saying, we can't keep putting all the weight on Auba's shoulders to score the goals. We need contributions.
"The midfielders need to score more and give more assists, and we need goals from our wingers as well. Laca is in great form and has scored five goals in his last four games, which is what we need from our strikers.
"Auba had some chances to score and it was the same in the last game or so, but I am so pleased because in the final third we looked lively and there was a lot of movement."
