Impact on Celtic’s foreign policy

Under the trerms of Brexit, they would face a battle to sign a player of similar calibre and background.

Likewise, Moussa Dembele, who took the Scottish game by storm last season and is expected to be sold on at a huge profit, has yet to be capped by France.

“March 2019 is not really that far off. Brexit is coming,” said Higgins.

“At the moment, all the different sports are throwing up examples of what might happen and trying to get some formulation in their mind.

“At some stage, there will have to be some discussion with government.

“If we followed the Norwegian model and retained free movement, there wouldn’t be much change.

“But if we leave the EU – if we leave the free market – then it is highly likely a work-permit system will prevail for the rest of Europe, affecting French, German, Dutch, Spanish players and so on.

“That is what most people are predicting. So there’s the potential for EU players, who are not already of international standard, facing a far more-rigorous interview and appraisal before they come into Scottish football.

“That is where discussions will have to take place for the relevant organisations to present the case for football.

“There is no way I can see the government saying we will give you a free pass. Other industries would say, quite rightly: ‘ Well, hold on a minute, what about us?’

“To gain a work permit, they would have to have some exceptional talent – or maybe be very young.”

If it is going to be trickier for the clubs at the top who have the financial resources to play with, it will be a total game-changer for those who don’t.

“If we leave the EU with a hard type of Brexit, clubs further down the levels may struggle to persuade a tribunal their targets should be allowed to come here,” said Higgins.

“The upside, though, of that is that home-grown talent could be given a better platform to develop.

“I say that because if our clubs no longer had easy access to the EU market, that would inevitably mean more opportunities for young Scottish players.

“At the same time, the Scottish market would be likely to become more attractive for English clubs further down the scale.

“I am talking about those in League One, League Two and the Conference, who maybe would look to bring in Europeans at a journeyman level just now.

“They would find it very hard to obtain work permits for that standard.”