Jose Mourinho has instructed executive vice-chairman Ed Woodward to sign a holding midfielder before the start of the next season after splashing more than £100 million on Victor Lindelof and Romelu Lukaku.

Dier, Chelsea's Nemanja Matic and Monaco's Tiemoue Bakayoko have all been mentioned as possible candidates. But sources said Dier is Mourinho's preferred choice with United willing to spend £50 million to prise the 23-year-old away from White Hart Lane.

There is a feeling at Old Trafford that signing Matic has become more difficult after United pipped Chelsea to Lukaku, Antonio Conte's top summer target.

Meanwhile, sources said United have very little interest in Bakayoko, who has been heavily linked to a move to Chelsea.

The Frenchman's impending transfer to Stamford Bridge raises the chances of Matic being allowed to leave, but Chelsea would rather see the Serbian move abroad than strengthen a Premier League rival.

United are well aware of how difficult it will be to negotiate a deal for Dier with Tottenham chairman Daniel Levy.

The England international signed a new five-year deal in September and Levy is keen to keep his promising squad together ahead of season which will see Spurs play their home games at Wembley while their new stadium is being finished.

United, though, can pay Dier double the £70,000-a-week he currently earns, a level at which Levy cannot compete thanks the strict wage structure he has put in place.

Dier grew up a United fan and counts former captain Roy Keane as one of his idols. In 2010, during his time at Sporting Lisbon, he admitted it would be "very difficult" to turn down United if an offer ever came in.

It has led United to believe that Dier would like to join this summer, with the hope that Levy does not price him out of a move by asking for a fee in excess of £60 million.