De Bruyne, once of Chelsea, is considered one of the world's elite midfielders and signed a six-year deal at City in January. "If it can be done, I would like to do it", Guardiola told the Universo Valdano show.
'(Leeds United boss) Marcelo Bielsa told me he was his favourite player.
De Bruyne was the star man as City smashed a string of records in romping to the Premier League title under the Catalan's leadership last term.
'The other day, I met his parents and you often understand how the children are when you know the parents. The clause is €250million. "I'm sorry, he is not for sale".
And the 47-year-old confirmed he also has ambitions to try his hand at worldwide management should the chance arise.
"My time there as a coach is finished because I'm not the same as I was then, nor is the way they see me the same", Guardiola said. "I want to try it".
Barcelona B play in the Spanish second division and give experience to promising young players who may eventually make the huge leap up to first-team football.
His contract with the club expires in 2021 and he has previously said he would not return to Barcelona as manager, although sporting director is a position that interests him.