Ronaldo, 24, admits he is still in love with ping pong in his forthcoming autobiography Momentos.
"After football, ping pong is my favorite sport," he says. "I love to watch professional games and I like to play.
"I began to feel a fascination for table tennis as a child because it is a very popular sport in Madeira, where there are several nationally competitive clubs.
"I started playing as a boy in my neighborhood and at school. When I moved to the school of Sporting, I kept playing ping pong.
"There were plenty of tables in the athletes' common and I spent good times there with my team-mates.
"One day the coach of the Sporting table tennis said, 'I've seen you play and I think you can become a good table tennis player. Want to get in the team?'. 'No, no thanks', I replied without hesitation. 'I want to be a footballer. Ping pong is a hobby, not a sport in which you want to be professional,' I said.
"He tried to persuade me again and again. I always said 'no', and he finally gave up. Football was my passion.
"I do not know if the ping pong has lost a good player, but I know that even today I enjoy playing.
"I play with the right, left... Without being boastful, I think I do pretty well. Even those who think they have a chance against me give up when faced with the facts."