Jose Mourinho is currently in a rather sticky situation with his club Manchester United sitting in seventh position and squad morale questionably low.
The Portuguese manager has an impressive resume, winning trophies in Portugal, Spain, Italy and England, but has famously never lasted longer than three seasons at one club.
Former Barcelona playmaker Andres Iniesta witnessed the rivalry first hand and claims that the hatred between the two sides was not as severe before Mourinho's appointment.
"You don't have to be for Barcelona or Real Madrid to know that the situation was unpleasant," Iniesta told Marca in a recent interview.
Iniesta explains El Clasico rivalry
"And the key component in that story was Mourinho.
"Whoever doesn't want to see that, is radical.
"You didn't see the rivalry that always existed before, it went beyond that, you saw hate."
The 34-year-old also stated that the Manchester United manager had a part to play in the hostility amongst the Spanish national side.
"The Barca-Madrid tension caused by Mourinho did much damage to the national team [Spain] and the teammates.
"That atmosphere developed and it was unbearable."
This will not come as a surprise to many fans who have followed the 'Special One's' career, with Mourinho leaving Inter Milan and Chelsea on bad terms following a run of bad results due to a disconnect but Jose and his players.
Mourinho's professional hatred for Guardiola is sure to continue as well, with the Spaniard's Manchester City already 14 points clear of the Red Devils.
The Citizens have already secured bragging rights over their counterparts after a convincing 3-1 victory over United at the Etihad Stadium a fortnight ago.
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