Jose Mourinho is "not confident" that Manchester United will tie star man David De Gea down to a new deal.

The 27-year-old has established himself among the world's best goalkeepers since joining from Atletico Madrid in 2011, winning the club's player of the year award in four of the last five seasons.

De Gea had been moments away from joining Real Madrid in 2015, but the move fell through and the Spain international signed a deal with United until 2019 with the option to extend it by an extra year.

Thibaut Courtois' summer move to the Bernabeu increased hope within the club that they could agree a new contract with De Gea, but manager Mourinho is unsure about the Spaniard's future amid links to Juventus.

"I am not confident," the United boss told Sky Sports ahead of Sunday's match against Everton. "But I'm not also... how do you say the opposite of confident?

"I am not worried. I am not more than worried. I cannot find the word in English.

"Let's see what happens. Only the club, David and David's people can answer to that.

"My comment is only one: everybody knows how good he is, everybody knows how important he is for Manchester United.

"And if Manchester United wants to be better than it is now and not worse than it is now, obviously that would be very important to keep David."