The Portuguese star could have joined Real Madrid's rivals after erstwhile Manchester United boss Sir Alex Ferguson "offered" him to the Catalans
The Portuguese star joined Madrid in 2009 for a fee of €94 million from Manchester United and has become a huge hit at the Santiago Bernabeu, winning the 2013 Ballon d'Or for his sensational performances for both club and country.
However, former Madrid president Calderon insists former United manager Sir Alex Ferguson attempted to engineer a move to rivals Barca for the attacker - but Ronaldo refused.
Asked whether the Scot tried to send Ronaldo to the Blaugrana, Calderon told talkSPORT: "It is totally true. In the few weeks he tried to avoid him going to Real Madrid, offering him to Barcelona.
"Barcelona were very happy but in that moment it was very crucial as Ronaldo said: 'I'm not going to any other club but Real Madrid.'
"That's why we signed the deal. Everyone was happy: Manchester United got the £80 million [€94m], Real Madrid got the best player in the world and Cristiano got what he wanted because players like him are not only looking for money, they look for glory, and they look for anyone who is giving them that opportunity to win titles, to be the best in the world, to win golden boots.
"There are only three, four or five clubs that can give him what he wants."
Ronaldo has scored 22 goals in 21 league appearances for Madrid this season, but it is his work ethic and determination that separates him from other players, according to the former Madrid chief.
"Cristiano is the best of the best because every day he gets up in the morning and his only obsession is to be the best. He wants to be better than the day before," Calderon continued.
"I always told players coming to Madrid that this is the most difficult time of your career because anyone who plays against Real is going to give 150 per cent of themselves in order to beat you.
"I think it is very important for young players to understand how important it is every time you are playing or working to want to be the best. I think that is the secret of Cristiano."