I don't even know what this rule is, dawg.
Barely any Spanish talent these days though so perhaps amendment to these crazy rules is needed.
It is UEFA rule, your squad for Europe need 8 homegrown from the federation that ypur club is under (so, for us, RFEF)
Out of the 8 players, you need 4 of them to be club homegrown.
Homegrown players are ones who played 3 years in the club/Federation between age of 15-21.
Araujo is few months short for example