Real Madrid Transfer News: Cristiano Ronaldo Future Doubted by Florentino Perez

Real Madrid president Florentino Perez has thrown some doubt over Cristiano Ronaldo's long-term future at the Bernabeu by suggesting there is no "guarantee" the Portuguese will end his career with Los Blancos.

Ronaldo is currently contracted with Madrid until 2018, and he has been their superstar player since joining from Manchester United for a then-world-record £80 million transfer fee in 2009.

Perez said two years ago Real fans could "rest assured" that Ronaldo would retire at Madrid, but now his stance has softened, per Spanish outlet Sport: "Cristiano Ronaldo is under contract and we want him to stay here in the future, but in life you cannot guarantee anything," Perez said.

The president did indicate, however, that it would be against his own wishes if Ronaldo was to cut his Madrid career short. "Today it's impossible to have a Madrid without Cristiano. He's the most emblematic and the best in the world," Perez added.

Certainly the 30-year-old Ronaldo is the key man in the Real side, and with his five goals against Espanyol at the weekend, he broke yet another club record, per Sporting Intelligence:

Along with Barcelona's Lionel Messi, he is widely regarded as the best player in the world at the moment, and undoubtedly one of the best ever.

Ronaldo has been linked with a move away from the Bernabeu a number of times, with recent reports suggesting Ligue 1 giants Paris Saint-Germain put in a £110 million bid for the forward in the summer, per Brazil's Globo Esporte (h/t the Mirror's Liam Corless).

PSG were, unsurprisingly, rebuffed by Real, and Perez recently insisted the French champions would need to meet Ronaldo's €1 billion (£733 million) release clause if they wanted to buy him, per Spanish radio station Cadena COPE (h/t ESPN FC's Adriana Garcia).

However, should Ronaldo decide to run down his contract, there will be nothing Real can do to stop him departing in 2018.

He will be 33 years old at the end of his current contract and in the twilight of his career. If a huge-money deal is offered to him by one of the top European clubs—most likely the affluent PSG—he may be persuaded to depart Madrid.

He could also follow in the footsteps of European stars Andrea Pirlo, Frank Lampard, Steven Gerrard and David Villa, who have opted to run down their careers across the Atlantic in MLS.

Whatever the situation, Real need to start planning for life after Ronaldo. Whether he remains past 2018 or not, he cannot keep up his extraordinary level of performance for much longer with age catching up with him.

Having added no galactico signings in the most recent transfer window, Real should be keeping an eye out for their next superstar, per Bleacher Report's Andy Brassell:

At 26 years old, Welshman Gareth Bale is the heir apparent to Ronaldo as the Spanish giants' No. 1 man, but he will not be able to win the Champions League and La Liga titles Madrid fans demand by himself.

Alongside Ronaldo, Bale forms one of the most devastating duo's in world football.

While there is still some time left before the pair will be broken up, Ronaldo's future at the Bernabeu past 2018 is by no means guaranteed, and Perez knows it.