I would think that it is just a formality, ticking the boxes and perhaps the Olympics thing was one of them? I know that the rules on signing South American players has relaxed recently hence us looking at players from there. Coming to Europe to play is pretty much a career path for players in South America often to their former colonial "masters" so Brazilians ending up in Portugal and Argentinians going to Italy and Spain.
The only concern with bringing a single Spanish speaker over to Boro is can he settle? Is he going to live with Leo? I don't think we have any other Spanish speakers do we?