It had been reported that the highly-rated 21-year-old had signed for United, but it seems this is not the case.
De Gea issued a statement through his lawyers to deny any agreement between the Liga club and United is in place.
"I hereby deny information that appeared in various media today indicating that David de Gea Quintana, football player of Club Atletico de Madrid, has signed for Manchester United.
It is not true that he has been signed," lawyer Jose Bouzas Aragon wrote.