Eden Hazard will be presented as a Real Madrid player following his 150-million Euro move from Chelsea.
Madrid expect more than 70,000 fans could welcome the Belgian forward at the Santiago Bernabeu, which would be more than those who turned out to see Cristiano Ronaldo in 2009.
The Spanish club's former president has told Sky Sports that Hazard has a tough act to follow.
"He's a fantastic player but Cristiano is unique. I've never seen or found a player like him, Hazard is very talented and skilful, he's proven that in the strongest championship in the world, which is the Premier League.
"He can play on both flanks, is a good dribbler with excellent passing. He can play in many positions - attacking midfielder, winger, even a false nine - so it is a fantastic opportunity."
As Hazard arrives in La Liga, there are doubts over Gareth Bale's future at Real Madrid.
Coach Zinedine Zidane froze out the Welsh attacker at the end of last season but has three years left on his one-million Euro a week deal at the Bernabeu.
Bale's been linked with a transfer back to the Premier League and Calderon thinks a loan move away could suit all parties.
"His situation here is very difficult, it is clear Zidane has discarded him in his mind. He showed that last season by not having him in the starting line-up. It is very disappointing for a player like him.
"Also the problem is the transfer fee. Real Madrid want to get a lot of money for him but I find that difficult.
"Maybe the best thing for everyone would be a loan. The player could recover his confidence on the field and Real Madrid could see his value rise.
"He wasn't successful here for many reasons - injuries, also the handicap of the money. When he came we paid more than we did for Cristiano.
"People thought he should be better than Cristiano but that is very difficult."