The Belgian admits he chose to stay with Manchester United ahead of the Azzurri.
He told Sportweek: "In 2014 I almost signed with Napoli, I had also talked to (Rafa) Benitez. I came from my first year with Manchester and it wasn't the best.
"I played a great World Cup with Belgium in the summer and I didn't know if I would have been with the Red Devils. I really thought about it, then I thought about it and I realized that United was a great club and the Premier was a great competition."
"They say he's crazy, but he's crazy in the good sense. They criticise him because he smokes, drinks or has fun ... who doesn't?"