Spain international De Gea, 28, joined United from Atletico Madrid in 2011.

His contract ends in the summer, which would allow him to talk to overseas clubs from 1 January and potentially sign a pre-contract agreement.

However, United have an option to extend the deal for another year.

De Gea's representatives are already working on the basis that his contract will expire in 2020.

As manager Jose Mourinho confirmed after Tuesday's 1-0 win over Young Boys, United are keen to hold on to the keeper, who has won United's player of the year award four times in the past five seasons.

It is understood De Gea is open to the idea of remaining at the club, although as yet, there has been no agreement on terms, with De Gea's camp mindful of the enormous salary United agreed to pay Alexis Sanchez when he joined from Arsenal 10 months ago.