The BBC queries sports lawyer Mike Townley on the legality of Uefa's home-grown rule:
"Where sport constitutes an economic activity, it is subject to laws in much the same way as banking or insurance services are.
"Professional clubs operate on a profit-or-loss basis and many are publicly quoted companies.
"As such, they are treated no differently to banking services, which could not restrict the number of Italian workers they had in their marketing department, for instance."
Sounds right to me. More discussion, quite good, is here.