Atletico Madrid striker Diego Costa, who has been granted a Spanish passport, was called up into Spain's squad to face Italy on Friday, despite the fact he is Brazilian-born and has even played for the World Cup hosts in two friendlies.
Mourinho said: "When, one day I'm a national coach, I will take only players born in my country. That's for sure.
"Or if not born in my country, then with parents with a big connection with the country.
"I will never take a player just because he has a passport from my country thinking he can make my team stronger. For me, the national team means a lot. My national team means a lot. If, one day, I coach Portugal, I'll go with the Portuguese.
"I won't do it. The national team is Portugal. It's not Portugal & Friends. Portugal is for the Portuguese."
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