The Spanish starlet, who helped his country to European U21 Championship glory on Tuesday, has found himself at the centre of a transfer tug-of-war since the 2012/13 campaign came to a close.
With Malaga's financial struggles well-documented, and with coach Manuel Pellegrini having decided to leave his post for one at the Etihad Stadium, it did not take long for Isco to become one of European football's hottest properties.
City and Real have led the chase from the start, and are known to have put offers to the talented 21-year-old.
They are now waiting to hear back, with conflicting reports suggesting that both clubs consider themselves favourites to secure Isco's signature.
Both are already well-stocked for creativity - with City having added Fernandinho and Jesus Navas to a group which already includes Samir Nasri and David Silva, while Real's midfield options include the likes of Luka Modric, Angel Di Maria, Mesut Ozil and Kaka.
Isco would face fierce competition for a starting berth at either club and is determined to make the right call for his career.
He has thought long and hard about his decision, keeping everyone waiting, but has now hinted that a lengthy transfer saga is nearing a conclusion.
He said: "I prefer not to comment about my future, but the matter could be closed this Sunday."
Reports emanating from Spain suggest City and Real could face competition from big-spending Paris Saint Germain and Borussia Dortmund for Isco's signature with both clubs thought to have tabled offers for the playmaker.