Real Madrid target David De Gea can only leave United for top fee - sources

Manchester United will keep Real Madrid target David De Gea for a further year if they do not receive a world-record transfer fee for a goalkeeper, sources have told ESPN FC.

United are willing to run the risk of losing the 24-year-old Spain international on a free transfer rather than sell him on the cheap.

De Gea is out of contract in 2016, is yet to sign the lucrative new deal United have offered and could leave Old Trafford for nothing in 12 months' time if he is not sold this summer.

However, Real are yet to match United's valuation of former Atletico Madrid player De Gea, who is currently back in his home city but has said he is only there on holiday.

ESPN FC has been informed that, if United were to sanction a sale, they would want a world-record fee for a goalkeeper and are reluctant to let him go the 24-year-old for anything less.

Gianluigi Buffon, who joined Juventus from Parma for £32.6 million in 2001, remains the most expensive keeper in football history.

De Gea, who cost United £18 million when he arrived in 2011, has been voted their player of the year for a second successive season.

Real and United also have differing values of defender Sergio Ramos, who United boss Louis van Gaal wants to bring to Old Trafford.

United have offered €40m (£28.4m) for the World Cup winner, a sum they believe is an appropriate price for a 29-year-old, but Real have held out for more.