City will face Manchester United at home in the Premier League on Sunday.
He said: “This is a game which rivals any derby in world football.
“Madrid v Barca is a huge rivalry and playing those games is extremely intense because you know just what it means to the fans. The pride of the club is at stake every time you play against Barcelona.
“Here, though, the derby match has another dimension because the two teams are here in the same city. And that means families and neighbours can be supporting opposing sides on the same day. I already know what this means to our fans.
“Everybody tells me everywhere I go. In the supermarket, in the street they stop me and say ‘Robinho, you must beat United. This is our game. This is our day’. I understand them and I love the passion.”
Robinho continued: “United are a club known all around the world. No matter where you grow up, if you love football then you’ll know about Manchester United.
“I saw United matches on TV as a kid in Sao Paulo. I loved watching Ruud van Nistelrooy.
“He was a hero for me because of the way he scored goals in all competitions.
“He’s such an intelligent striker and I have tried to copy his technique to improve my game even though we are not similar players.
“When I signed for Real Madrid, it was like a dream. I walked into the changing room and there was one of my football heroes.
“I feel very lucky that I got to play with a guy who I worshipped from far away and I am very proud to call him my friend.
“We still stay in touch and speak on the phone very often.”