Florentino Perez, the president of Real Madrid, has a net worth of $1.8 billion, according to Forbes. He is one of Spain's most powerful people, on the same footing as the chairman of Santander bank and the prime minister.

Perez has a taxing day job. As head of the construction firm Grupo ACS, he has more than 200,000 employees worldwide. He oversees building projects in almost every corner of the globe—from subway stations in New York to wind farms in Brazil. He negotiates contracts worth billions of dollars and makes big business decisions all the time.

Yet when it comes to football, it's difficult for Perez to make up his mind. Real Madrid has 91,730 members, the club reported in its latest annual statement. They own the club and vote their president into office. And when Perez has a big Madrid decision to make, he gauges the members' reaction first.

The biggest looming decision for Perez is whether Real Madrid should sell Cristiano Ronaldo. It's personal with Perez, and it goes back to the start of Ronaldo's story with Real Madrid.

It is ironic, given all the goals Ronaldo has scored for Real Madrid—he's averaged more than a goal a game, including a record haul of 17 goals in last season's Champions League-winning campaign—that Perez almost blocked the move to sign Ronaldo from Manchester United six years ago.

Real Madrid began their hunt for Ronaldo during Ramon Calderon's tenure as president. Calderon and Ronaldo agreed that the player would move to Real Madrid in 2008. Before the Portuguese winger signed a contract, though, Manchester United manager Sir Alex Ferguson convinced him to stay in England for another year. Real Madrid were playing a friendly match in Bogota, Colombia, when news of the postponed deal filtered through to Calderon.

Ronaldo with Florentino Perez, in 2013 Getty

"I got up in the morning to receive a phone call from Real Madrid," Calderon told Bleacher Report. "They said, 'You know what? Cristiano has announced that he's extended his contract.' I said, 'It can't be.'

"Fifteen or 20 minutes later, I got a phone call from Cristiano, saying, 'Mr. President, I'm so sorry. I have to do this because I'm quite happy with the club. Ferguson is like a father to me. I'm in love with the fans, everything here, but we have an agreement I will go next year.'

"I said, 'Of course. It's up to you.' So we arranged everything for the next year. We got all the documents done."

Ronaldo left Manchester United for £80 million the following June. Everything was done by December 12, 2008.

Calderon left office in January 2009, a month after the deal was inked but before it had been officially announced. Perez returned for his second coming as president in June 2009, yet he balked at signing Ronaldo, even though there was a £30 million penalty clause in the contract in case any party withdrew from the deal.

"The problem was that when Florentino came, he said, 'This is not a player for Real Madrid,'" says Calderon. He didn't like to receive inheritances that he couldn't be proud of in the future. He thought, 'This player is not mine. I'm not going to take advantage of this.' He said, 'I think I can have two or three players for the same money. I don't see Cristiano Ronaldo playing at Real Madrid.'

"The player knew that. He got very angry. His agent, Jorge Mendes, said, 'OK, we're going to leave. We are not going to claim the penalty clause.'"

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Fortunately for Real Madrid, their general manager at the time, Jorge Valdano, convinced the president not to make a rash move on Ronaldo. Calderon says that Valdano told Perez to calm down and not let his pride get in the way of signing the best player in the world. Perez was suitably pacified, but those events are why Ronaldo was unhappy during his first two or three years at Real Madrid.

In September 2012, Ronaldo's state of mind became a global talking point—he has more than 100 million fans on Facebook, a greater cohort than any other sports star. He announced he was "sad" because of his situation at the club, per Andy Brassell on BBC Sport.

According to Juanma Trueba, deputy editor of AS, Ronaldo was upset because Perez failed to turn up at the UEFA Best Player in Europe Award ceremony in Monaco. That prize went to Andres Iniesta, who was accompanied by Barcelona's president at the time, Sandro Rosell.

It seems Ronaldo suffers for being an ugly stepchild in the eyes of Perez, especially compared to the other Galactico signings. When it comes to the likes of James Rodriguez and Karim Benzema, Perez indulges those players. They're his adopted sons.

Perez took time out of his business schedule to fly to Benzema's house in Lyon, France, to coax him into joining Real Madrid. He also sold striker Gonzalo Higuain, who was signed by Calderon, and replaced him with Javier Hernandez, a squad player who wasn't a rival to Benzema. And there are no players who Perez indulges more than Gareth Bale.

According to Diego Torres, a journalist with El Pais, Real Madrid would sell Ronaldo before his younger, buccaneering team-mate Bale. At this moment in time, however, it wouldn't be acceptable to sell Ronaldo politically. Fans would kick up a fuss. Perez must bide his time.

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"Florentino doesn't like Cristiano," says Torres. "He didn't buy him. Florentino dreamed of Bale as a Golden Shoe winner, scoring spectacular goals. His dream is to switch Cristiano with Bale because he created Bale as a superstar. He made him the first €100 million player. He feels Bale is his creation, that everyone relates Bale to him, to Florentino."

Perez, Ronaldo and Mendes declined requests for interviews regarding Ronaldo's future at Real Madrid.

Despite Perez's reported wishes, Bale may not be ready to take the reins from Ronaldo. The Welshman underperformed in Madrid during his second season. He's struggling to integrate. He doesn't speak Spanish. He has only one close friend in the squad, former Tottenham Hotspur team-mate Luka Modric.

On the field, Bale lacks Ronaldo's guile. Ronaldo has adapted better to the game on the continent. He can navigate tighter spaces. He's smarter at arriving in scoring positions, and Bale has been shunted out of position to accommodate Ronaldo.

"Florentino keeps saying Bale should become the next Ronaldo, the next megastar, the next flagship of the club, but it's very difficult for Bale," says Torres. "If Ronaldo were not at the club, it would be much easier for him. Real Madrid fans love Cristiano, but once he stops scoring as many goals, they will start to criticise him and jeer him."

The Santiago Bernabeu Stadium is one of the most hostile sporting arenas in the world—and that's for Real Madrid's own players.

"Fans of Real Madrid have an identification with success," says Calderon. "It's not about football. 75 per cent of them are not born in Madrid, so it's not the same as Barcelona, Sevilla or La Coruna, who think the club represents the region. We go to the stadium like it's the opera. If they're not singing right, you just boo, whistle and wave the handkerchiefs. It's something that players, when they come here, they don't understand. 'Why are they booing us? They are not backing us.'"

Ronaldo has experienced this impatience. In March, during a minor blip in form, he was whistled at while playing a league match at home against Levante. In the same month, a poll conducted by AS found 32 per cent of respondents believed he should be dropped from the team. At the time, he had scored 31 goals in 25 league matches. It is difficult to comprehend how he could be so unloved.

It seems Ronaldo's narcissism gets on the nerves of Real Madrid fans. The bare-chested, he-man pose he broke into after scoring a penalty against Atletico Madrid in the 2014 Champions League final, for example, grated. The traditional Madridista is disgusted by those kinds of gestures of superiority and the fact that he rarely celebrates his team-mates' goals. He only celebrates his own goals.

"If Real Madrid wins and he doesn't score a goal, he's sad," says Trueba. "He has an infantile ambition that doesn't allow him to see that the benefit is for the whole team. He's like a 10-year-old. He wants all the cake to himself, and he doesn't understand that he has to share."

Instead, players such as Sergio Ramos and Isco, who are relentless in their scrapping to win the ball back, are crowd favourites at the Bernabeu because of their tenacity. Real Madrid's supporters love the luchador—the fighting player. It comes from the spirit of club legend Alfredo Di Stefano, who was insatiable in his harrying of players for the ball.

Trueba stresses that Ronaldo is not "a bad person." He may be egocentric, but he is friendly. He doesn't have enemies. Even though Bale could be perceived as a threat to his position, and strike partners have been known to operate without speaking to each other, Ronaldo speaks well of Bale. He asks journalists and fans to be patient with Bale.

Ronaldo is also a model professional, and he's not a bolshie influence in the dressing room like, for example, Ramos, Iker Casillas and Ronaldo's former team-mate Raul, who have caused headaches for their coaches.

Ronaldo celebrates 2008 Champions League glory with Man Utd Alex Livesey/Getty Images

How much longer will Perez keep Ronaldo? It seems inconceivable he would sell the goose that lays the golden eggs. Could he be so blinded by his own megalomaniacal team-engineering goals? Ronaldo's buyout clause is a cool €1 billion. The figure is set prohibitively high, but nothing in the world of football transfers is undoable. Other clubs, notably Paris Saint-Germain and Manchester United, would surely covet the Ballon d'Or winner.

"He's the second-best player in the world," says Andy Mitten, journalist and editor of Manchester United fanzine United We Stand. “Manchester United are obviously interested in someone that is (a) that good (b) successful already for the club and (c) adored by United supporters.

"As with everything, it's about price. There is definite interest. United tried to sign him in 2013. Contact was made. At times, Manchester United's top brass felt they had done the deal, that the deal was achievable."

There is anecdotal evidence that United are again interested in buying him, but it remains an inopportune moment politically for Perez to sell a player who is scoring 50 goals a season. It would cost the president votes.

"It would be unthinkable for Real Madrid to sell Ronaldo," says Michael Robinson, a European Cup winner with Liverpool in 1984 who now hosts an award-winning sports show on Spanish television.

"Perez collects football players. He doesn't sell his jewels. Ronaldo is an object of desire. Whether Real Madrid fans personally like him, they perceive him to be the Ballon d'Or, the best player in the world. The best player in the world has to play for Real Madrid, and it's impossible to have Lionel Messi."

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Ronaldo also has a say in his future. "It comes down to the player, whether he is happy or not," says Calderon. "It could happen he says he would like a change. He has other opportunities. Does he want to go to England or Portugal? I think he is quite happy at the moment. He is enjoying his life here in Madrid. He likes the city where he is living."

Ronaldo has previously said he would like to finish his career at the club, according to BBC Sport. He is, however, 30 years of age. He covers less ground and forages for his goals 20 metres farther up the field than when he first arrived in Madrid. He has been troubled by a persistent knee injury, which caused him to limp out of last year's World Cup.

"He's tired. The play of Cristiano is fundamentally physical. He's not like Messi. He's a beast, a machine. The age will pass a bill to Cristiano," says Miguel Angel Linares, author of a book on the rivalry between Real Madrid and Barcelona entitled Madrid-Barca: ¡Es La Guerra!

Ronaldo is not Real Madrid's first icon. Others such as Di Stefano, Emilio Butragueno and Raul, whose goalscoring record at Real Madrid will be surpassed by Ronaldo within a year at his current scoring rate, have come and gone. Significantly, none of them finished their playing careers at the club.

Sport is a brutal marketplace that way. Real Madrid, especially while fronted by a president who casts a cold eye on his inherited livestock, could look to cash in on Ronaldo.

Perhaps not this summer, but within a year, the club might think it's time to say, "Adios, Cristiano."

Richard Fitzpatrick is based in Barcelona and the author of El Clasico: Barcelona vs. Real Madrid, Football's Greatest Rivalry. He contributes regularly to the BBC, New York Times, Irish Examiner and Irish Times.