The United shot stopper refused to extend his contract and may switch sides.
Arrival of Victor Valdes may or may not have caused problems.
Real Madrid club president Florentino Perez is keen to bring De Gea back to Spain, this time against city rivals and Champions League winners.
David De Gea earlier was placed second at Atletico Madrid at the age of 17. But Sir Alex Ferguson brought the then 19-year-old Spaniard to BPL and also played against Real Madrid during 2012-13 season.
The Spaniard then grew into one of world's best and without doubt, the finest in his position this term.
His heroics against Everton, Liverpool, Arsenal and Man City this season cant be forgotten.
Madrid are said to spend 38 million euros for the 22-year-old, but Madrid dont really need him right now.
With two of La Liga's best keepers in the squad, the arrival of De Gea may cause problems. Iker Casillas had already not been in a good mood with his international teammate during their time at Spain dressing room.
De Gea was in favour for Del Bosque instead of Casillas after the World Cup.
The departure of one goalie may happen due his arrival. Navas has been a second choice so far.
Right now, though both goalies are not in their peak, Madrid doesn't another shot-stopper.