The Ivory Coast defender moved to Premier League rivals Liverpool in the summer having struggled to gain first-team action in his final season at the Etihad Stadium.
Toure has already made eight league starts for his new club and feels he has proven a point to City.
"I was better than certain players at Manchester City but I was left on the bench," the 32-year-old told The Sun.
"Before I left the club, I told the people in charge that they would regret letting me go. People said I was finished and that I could never get back to my former level.
"But now I am at Liverpool - and I am sure that City must be kicking themselves when they see how I am performing."
Toure sees similarities between his own situation and the one brother Yaya faced when leaving Barcelona to join City in 2010.
"I have had a similar experience to Yaya," he added. "Managers come to clubs bringing players with them and they want to pick them at all costs - whether they are any good or not.
"Yaya was much better than Sergio Busquets at Barcelona. But he was behind him in the pecking order and he found that hard to accept.
"I advised him to come to Manchester City while I was still there. He listened to his big brother's advice - and now he is the big boss on the field for them."
