It is expected that the 21-year-old playmaker, who is currently in action at the European U21 Championship, will be on the move this summer.
Manchester City and Real Madrid are leading the hunt for his services, with City hoping that the appointment of former Malaga coach Manuel Pellegrini as their new boss will work in their favour.
Isco is giving little away when it comes to his next move, with his focus locked on the pursuit of international glory - with Spain having booked a final date with Italy in Israel.
He is, however, ready to bring an end to months of speculation by revealing the identity of his preferred transfer destination.
Isco said: "In seven days I will decide my future.
"After the U21 Euros I will analyse my situation and make the best choice for my future.
"At the moment I am calm and focused on my work with the national team.
"City or Madrid? I can't say. Pellegrini is a great coach, though, of that there is no question."