Mendieta sampled the intensity of the game during a season on the books of the Catalan giant and his experience has left him in no doubt that the contest is without equal.
"I was lucky enough to have played in the fixture when I was at Barcelona. I think that is the best game that you could possibly play in at club level," Mendieta told Goal.com. "I played in the Rome derby between Lazio and Roma which was nearly at that level in terms of intensity and I know that derbies in England are very passionate, but for me the Clasico is the most amazing derby there is, anywhere.
"That is because of the type of football that is played, which is mesmerizing at times, but it is also because of the electric atmosphere at the games as well. It has everything that you could want as a player or as a supporter. There will be 110,000 people at the Nou Camp which will be absolutely incredible. It is so good it is almost indescribable. They are eternal rivals.
"The rivalry between the two clubs is an historic thing but it is so intense because these days in Spain it is about Barcelona and Real Madrid more than ever. It is one or the other that wins the league whereas Valencia or Atletico Madrid, or even Deportivo La Coruna, used to be involved in the title race."
With Barcelona trailing leader Real Madrid in La Liga and both teams having been beaten in their Champions League semifinal first legs the stakes could not be higher ahead of the weekend's meeting between the two.
"It will be a great game because Real Madrid are desperate to take Barcelona’s crown away from them in the league and maybe in the Champions League as well," added Mendieta, who also played for Valencia, Lazio and Middlesbrough.
"It will be very difficult for Barcelona to take if they let Real Madrid win the championship although Real Madrid’s fixtures are not easy because, apart from El Clasico still having to be played, they also have to go and play against Athletic Bilbao which will be a very hard game and Bilbao will be aiming to knock the title out of their hands if they still have it."
Barcelona may have home advantage but the former Spain international does not believe that guarantees a win for Guardiola's team against Jose Mourinho’s charges.
"In the Clasico anything can happen," he continued. “They are both great teams who have been playing well but you would have to favor Barcelona because they have their fans behind them and they also have the advantage of playing on a bigger pitch which suits their style of play.
"They seem more comfortable when they are playing there, especially Messi, and they score more goals at the Nou Camp than they do in any away games. But it is El Clasico and so anything can happen."
Mendieta played down suggestions that Real Madrid have an inferiority complex, instead insisting that Mourinho's side are simply challenging the greatest team in the history of club football.
"I don’t think Real Madrid have an inferiority complex when they play against Barcelona. I think that unfortunately for this Real Madrid side, which is probably one of the best Real Madrid teams in history, they are playing against the very best Barcelona team in the history of the club and club football as a whole," he explained.
"So in another era, Real Madrid would have won everything but they have to overcome the best club side ever and that is not easy to deal with. Real Madrid have Cristiano Ronaldo who is amazing but Barcelona have Lionel Messi and he is the best player in the world.
"Jose Mourinho often confronts the media and deals with the pressure in his own way but that is so he can take the pressure away from his players. But whatever you say about Mourinho he is a very successful manager. You cannot argue with that."
Mendieta spoke to Goal.com while in England to publicise the SABIC 5k Riverside Run in Middlesbrough on Sunday, May 13. For details go to www.runmiddlesbrough.com.