The Gremio man was unable to make an impact at Los Blancos, but he feels he could have been a big hit if it were not for his desire to play at the 1998 World Cup in France
The 38-year-old joined Los Blancos from Portuguesa back in 1997, but quickly headed back to Brazil with Flamengo so as not to endanger his spot in the Selecao's 1998 World Cup squad.
"I left Brazil very young, particularly when you take into account I left a so-called small club like Portuguesa to join a genuine giant like Real Madrid," Ze Roberto was quoted as saying on the official Fifa website.
"I knew that I was going to need time to succeed over there. But I dreamt of playing at the World Cup and had been a [national team] regular from Under-23 level, so I had a very frank conversation with [then coach Mario] Zagallo. He told me that he saw me as part of the squad, but only if I was playing regularly.
"I knew that if I wanted to cement a starting place at Madrid I'd need to stay for a few years. So, with the World Cup in mind, I left Real and joined Flamengo. I believe that if I had have stayed [at Madrid] I would have been a success, however fierce the competition was."
Ze Roberto, who is now back in Brazil with Gremio, also represented the likes of Bayer Leverkusen, Bayern Munich, Santos and Hamburg earlier in his career.