Jamie Carragher says Manchester United must walk away from a deal to sign Borussia Dortmund's Jadon Sancho if they don't think they will be able to negotiate a fair deal for him.

The MEN understands Sancho remains United's top transfer priority despite protracted negotiations to sign the winger.

Calls for a new centre-back to be bought have increased over the last week too, following their 3-1 defeat by Crystal Palace last weekend. The MEN understands United are open to signing a new central defender, although it is not a priority position for them to strengthen in.

On the issue of Sancho, Carragher said in his Telegraph column: "United’s hesitation in meeting Sancho’s valuation so far in this transfer window feels like it is an attempt to reverse the culture of overpaying.

"As fine a player as Sancho is, is he worth £108 million? And what impact would such a deal have on the game time of Mason Greenwood, who looks like the best young attacking talent in the country by some distance, scoring 17 goals last season?

"If United think Sancho is worth it, the deal should have been done already. What I cannot understand is if United do not think so, why haven’t they moved on? If the deal is not right, regardless of how much it upsets fans, walking away and buying an alternative target can be a sign of strength, not weakness."

Carragher also accused United of short-termism both with their managerial appointments and signings in recent years.

He said: "When United recruited Jose Mourinho, they were seduced by the idea of appointing a world-renowned coach rather than the right match for their club. Manchester City had just lured Pep Guardiola, so United wanted to respond with their own elite name despite obvious concerns as to whether Mourinho fit Old Trafford ideals.

"When that failed they installed a club legend, Ole Gunnar Solskjaer, to successfully pacify fans and buy time. Solskjaer was given the job full time after the uplift of a good start. That was because the fans loved the idea, when the board knew he would never have been a candidate for the role at any other elite club.

"The same short-term principles have been applied to most of United’s transfers since 2013, with every coach able to calculate that when the pressure intensifies, the cheque book will open amid the clamour to ‘stop haggling and pay whatever it takes’.

"Look at the signing of Alexis Sanchez, which was more about the vanity of gazumping Manchester City than a shrewd, necessary purchase. City acted like the bigger, better club by saying no when the wages became ridiculous."