Kompany left City at the end of the 2018-2019 season, in which he led them to a domestic clean sweep, to take up a player-manager role in his native Belgium.
He has endured a stumbling start to life back at Anderlecht, though, and has already stepped back from managerial duties on matchdays.
De Bruyne has backed his compatriot to turn things around, however, with the City playmaker even offering to join Kompany's squad in the future.
"I hope his career will be just as amazing at Anderlecht as it was at City," De Bruyne told The Sun of international colleague Kompany.
"I've told him to keep a place in his team for me in a year, or seven, when I'm finished here [at City].
"If he does do that for me I will already have my next destination lined up; my next job.
"I will definitely miss him being around City."
Kompany's testimonial will be played at the Etihad Stadium on Wednesday.
And De Bruyne gave an insight into the role played by Kompany in his decision to join City.
"At the time City were trying to sign me from Wolfsburg and Vinny was pushing for me to move to Manchester to play alongside him," De Bruyne added.
"He would constantly ask me when I was coming. He would say 'you need to come', constantly encouraging me to join City."