The Red Devils have all but secured the signature of former Barcelona stopper Victor Valdes on a free transfer, which had led to speculation that the 32-year-old could replace the Los Blancos target.
Real have been chasing De Gea for much of the latter half of 2014, with replacing veteran goalie Iker Casillas at the end of the season a pressing concern at the Bernabeu.
Although a former Atletico Madrid star, the United man is seen as the ideal candidate, and the European champions are believed to be confident of tying up a deal.
But Louis van Gaal is determined to keep the 24-year-old at the Theatre of Dreams, which has led to rumours that the club are fast-tracking plans to extend his contract.
De Gea’s current deal expires in 18 months’ time, and United chief Ed Woodward is planning to sit down with the ‘keeper’s agent, Jorge Mendes, before the month ends.
The player himself is happy in Manchester, although a move back to his homeland is appealing to him as he plots to establish himself as Spain’s No. 1.