Guardiola led the Citizens to a record-breaking Premier League winning campaign during the 2017/18 season and is widely expected to spend big over the coming months to further improve their squad.
Real playmaker Isco has been earmarked as a potential marquee signing, despite becoming an integral part of the Spanish side's recent UEFA Champions League domination.
However, speaking at an event in Barcelona, Guardiola put an end to the speculation; "No, Manchester City are not going to sign Isco."
In reference to Los Blancos recent third successive UEFA Champions League triumph, he lauded the 'quality' of the current crop of players and current coach Zinedine Zidane.
"When a team wins three consecutive Champions Leagues, four in five years, it's because they're a spectacular team," Guardiola enthused.
"The Champions League is a really, really tough competition -- staying in it depends on a lot of things. If all these things are with you for three straight years, it's because you're in control of them.
"To win three Champions Leagues in a row shows the quality of the team, the coach, the club ... as for everyone else, try to make sure now they don't win a fourth."