Real Madrid have reportedly renewed their interest in De Gea.
The goalkeeper came close to joining the Spanish giants in the summer of 2015, but a deal collapsed in the final minutes of the transfer window.
Spanish outlet Marca claim the La Liga club could now make a £55million move for the Manchester United goalkeeper at the end of the season.
Juan Mata insists David De Gea is happy at Manchester United
I've not spoken to him about this at all. He is relaxed here
Manchester United star Juan Mata
De Gea has insisted he is happy at Old Trafford, and Mata says the goalkeeper appears relaxed at United.
"David is a veteran here already, been here many years," Mata told Spanish radio station Cadena SER.
"Everyone recognises his contribution to the team.
Man United stars snapped arriving at Carrington as Watford preparations continue
Thu, February 9, 2017
Manchester United players arrive for training… but one player doesn't want to be seen!
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Jose Mourinho didn't look too excited as he was driven to Carrington
David De Gea is under contract at Manchester United until 2019
"More rumours have come out? If we are just in February, imagine until June, July, August … I did not know that it had come out again.
"He had a hectic summer before.
"I've not spoken to him about this at all.
"He is relaxed here, and with too much to think about for the rest of the season, without thinking about the summer."