The Belgium star says there was no way he could imagine the success he's enjoyed when struggling to make his way at Stamford Bridge.
He recalled: "My departure from Chelsea? I decided to leave because I felt I didn't have a chance to play at the time. I didn't see any other opportunities coming up, so for me it was the best decision to leave Chelsea and find myself in a situation where I felt I could start over.
"Did I expect it to end like this? Of course not, because at the time it was a very bad experience in my career, but I never doubted my abilities as a football player.
"Eight years ago, I couldn't imagine playing for City, making the World Cup and all that."