Madrid, Sep 4:Real Madrid president Florentino Perez has slammed English football club Manchester United, stating that goalkeeper David de Gea’s transfer to the Spanish team collapsed because United took eight hours to send contracts back to Santiago Bernabeu.Both clubs had agreed on a transfer but the move did not go through as time ran out on the deadline day at midnight on Monday in Spain with de Gea now staying in Manchester until at least January.Perez said, de Gea’s agent Jorge Mendes told Madrid, that United were willing to sell the goalkeeper, and the club’s director general Jose Angel Sanchez struck a deal with the Premier League club’s vice-chairman Ed Woodward “in about half an hour”.(Also Read: Real Madrid blame Manchester United for Devid Gea’s failed transfer)Also Read - Manchester United Confirm Agreement With Real Madrid For Raphael Varane's Transfer

“What they (United) lack is experience. We have missed out on players before, Franck Ribery and Patrick Vieira for example, but what is surprising is that someone wants to do a deal and only starts the process 12 hours before,” Perez was quoted as saying by Spanish radio station Cadena Ser on Thursday.”It’s the inexperience of the new people in charge. We have worked with them before (without problems), with Peter Kenyon and David Gill and with Sir Alex Ferguson.”Perez added that things like these have happened in the past and he wanted to learn from the previous mistakes. Also Read - Lionel Messi or Cristiano Ronaldo? Manchester United Star Mason Greenwood Joins GOAT Debate

“We still have good relationship with Manchester United but this is the exactly the same as happened before with Fabio Coentrao and Ander Herrera and we thought they would have learned from what happened in the past,” the club president said.”Manchester United had all the papers but they took eight hours to return them. We couldn’t buy him before because United didn’t want to sell him. De Gea is very upset because he was very excited about coming to Madrid.” Also Read - Real Madrid Boss Florentino Perez Lands in Fresh Controversy; Calls Ronaldo, Mourinho 'Imbecile' in Leaked Audio