Real Madrid president Florentino Perez has accused Manchester United of taking eight hours to complete the paperwork which would have taken David de Gea to the Santiago Bernabeu.
The Spanish goalkeeper looked set to make the switch on Monday after a deal was agreed, but the transfer was not completed before the deadline and both clubs have since released statements defending their role in the collapse of the move.
However, Perez believes that the mistake was another example of United's struggles with transfers.
"De Gea was very affected because he really wanted to come to Real Madrid," Perez told Cadena Ser. "At 1.30pm, Manchester United already had the contracts. We sent the contracts to Manchester United at 13.30 and they took eight hours until they sent back the papers.
"We don't understand why they took eight hours to see the contracts and we don't understand that if they wanted to negotiate, they waited until the last moment.
"We do not understand many things, but I'm not here to blame anyone. They lack experience, because this same thing happened last year to [Fabio] Coentrao and Ander Herrera."
Reports have suggested that United will attempt to keep De Gea by offering him a contract extension for a final time.
