The Premier League giants will have to break the world transfer record to sign the Spain international, according to a fresh report.
Spanish news outlet OK Diario (h/t Alex Wood of the Daily Express) reported Los Blancos president Florentino Perez will not allow the player to leave the Spanish capital unless his gigantic release fee is met in full, with Chelsea and Manchester City both considering the attacking midfielder.
Journalist Eduardo Inda has claimed Isco has had offers from the Premier League giants.
Per Wood, Inda said:
"They [Real Madrid] consider that Isco is not involved in the group, that he is doing his thing, that he is having problems with his weight… so he is thinking of going to the Premier League.
He has an offer from Chelsea and another from Pep Guardiola at Manchester City. I think that in a style of play like City’s he could do very well. Cristiano Ronaldo did not like to play with him because he said he kept the game a lot."
Isco has fallen out of favour at the Santiago Bernabeu Stadium in recent months, and recently appointed manager Santiago Solari has used him sparingly.
The 26-year-old was on the substitutes bench on Saturday as Real beat Valencia 2-0 at home in La Liga, making his way onto the pitch with just 10 minutes remaining.
However, the hosts sealed the points with a second goal three minutes after Isco's arrival, with Real climbing to fifth in the Spanish standings.
Solari has claimed there is no rift or problem with the former Malaga talent ahead of this weekend's clash with Los Che.
According to FourFourTwo, Solari said:
"Honestly, I think there's not really anything to talk about here. I spoke the other day. These are things that happen, they are decisions that have to be made. That's it. I can't be speculating all the time here with you guys. There are 24 professionals, they are all working hard and we have to take decisions. There's nothing more to say."
Squawka Football highlighted Isco's miserable period at his club this term:
The reported contractual figure for Isco's escape from Madrid appears ridiculous on the surface, but Perez knows the player could command a significant fee on the open market. No club will surely pay £620 million, with Los Blancos likely to be forced to taper their valuation expectations.
Isco would be a fine addition at Chelsea under manager Maurizio Sarri, but a dream move to City could see him take his career to a new level. Guardiola would be the perfect coach for the Spaniard, and Isco's experience of winning major European trophies would be hugely appreciated at the Etihad Stadium.
The Premier League is the most financially attractive domestic competition in the world, and Isco could further his personal brand at one of England's major clubs.