The Manchester City great had his presentation on the weekend in Naples.
Lukaku said: "Did I advise De Bruyne to come? No, I didn't give him any advice.
"He's a very simple boy, very attached to his family. The only thing I told him was to come here, to prove himself, and to be ready, like he always did at Manchester City and with the national team.
"I've known him since we were 13; everyone knows our relationship. I'm very happy that he's here, but it was he who made the decision to come to Napoli. And we're all very happy."