City are without the Belgium worldwide due to a knee injury that is set to rule De Bruyne out of action until November.
Now in his third season with City, he is hoping to defend the Premier League title they won last season with a record-breaking points tally of 100 and has already hinted at staying in England for a decade.
Guardiola, who will be without the playmaker's service until November, has now praised the 27-year-old, revealing that he would not sell him for any price.
'(Leeds boss) Marcelo Bielsa told me he was his favourite player. "I recently met his parents and understood a lot about why he is a fantastic guy".
"He's an incredible boy. I'm sorry, he's not for sale".
Prosecutors file new charges against Paul Manafort, signaling a plea deal
Any deal would not be final until Manafort admits guilt before the judge, who would need to approve the plea. A mistrial was declared on the remaining 10 charges after jurors could not reach a unanimous verdict.
Guardiola has previously ruled out returning to Camp Nou to coach the senior Barca side but has been linked with a possible return as sporting director.
And the 47-year-old confirmed he also has ambitions to try his hand at global management should the chance arise. "And I said, "When there is trouble, he will be there". "I want to try, for sure. if they want me".
Like De Bruyne, Guardiola has committed his future to City with a contract extension and the former Barcelona and Bayern Munich coach is settled at the Etihad Stadium.
"Here [City] I feel very good, very protected from football", he said. "The club knows my opinion and we share that and after that it is [up to] the club and Raheem's agent".