The Red Devils stopper has been heavily linked with a move to the Bernabeu for some time, with rumours having suggested that Los Blancos see him as an ideal replacement for their current legendary goalie – whose form has nosedived in recent years.
However, a switch looks unlikely unless Casillas is shipped out this summer, with De Gea reluctant to join if his compatriot is still around.
Reports suggest that the pair have a frosty relationship after Spain’s World Cup humiliation last summer, which could be a problem.
Such developments will come as good news for United, with their glovesman having been, arguably, their star performer this season.
Real are now looking at Bayer Leverkusen’s Bernd Leno, as Casillas is believed to be keen to stay.