Depends what EU passport he's after, if it's Spanish or Italian, as is standard with Argentineans then you're right, however the only European ancestry we've heard is Scottish, so that would probably give him a UK passport, which obviously wouldn't be affected by brexit
Interested in Thievy Bifouma, who was once of upcoming cup opponents WBA
https://twitter.com/LiveTransferNew/status/1083446735169613824?s=19
At least we have a chant all ready for him...