Squad rules requiring a number of homegrown players are frequently described as limits on foreign signings. The definition used shows they are something else.
The definition is about training, not passports
A homegrown player is typically one registered with a club in the same country for a set number of seasons before a specified age, regardless of nationality.
A player born abroad who joined a domestic academy young therefore qualifies, while a domestic-born player developed overseas may not.
The rule was drafted this way because quotas based on nationality would conflict with employment law in jurisdictions guaranteeing free movement of workers.
The incentive falls on academies
Because the qualification is earned through years of training, the rule creates demand for players who spent their development at a domestic club.
Clubs respond by investing in academies and by signing young players early enough for the clock to run before the age threshold.
That second response is the criticism. A rule intended to encourage development can be satisfied by recruiting teenagers from elsewhere, which shifts spending toward scouting rather than coaching.
Club-trained subsets tighten the requirement
Some competitions distinguish between players trained anywhere in the country and those trained at the registering club itself.
Requiring a portion of the quota to be club-trained closes the loophole of buying homegrown players from rivals.
It also raises the value of academy graduates within a squad, since a club-trained player occupies a slot no signing can fill. A club without them competes with a structurally smaller squad.
Squad lists are where the rule bites
Quotas apply to a registered squad list of a fixed size rather than to matchday selection.
A club short of qualifying players does not sign extra ones; it simply registers a smaller squad, leaving slots empty.
This is why the constraint appears as a planning problem in the transfer window rather than as a selection problem on a matchday.
Under-age players sit outside the count
Players below a stated age are usually exempt from squad registration entirely and may be selected without occupying a slot.
That exemption gives clubs a reason to promote young players earlier than they otherwise would, which is the rule working as intended.
The combined effect is a squad structure shaped by two thresholds, an age and a training count, both of which sit in the regulations rather than in any coaching judgement.

