Regardless of who is named Manchester United's permanent manager, big changes are in store for the 20-time Premier League champions this summer.

A new centre-back is of the utmost priority and it's claimed Napoli's Kalidou Koulibaly is the man club chiefs want.

Koulibaly, 27, is world class and and would represent a major improvement on most of United's current crop of centre-backs. He would cost them upwards of £80m, though.

Atletico Madrid's Lucas Hernandez and Fiorentina's Nikola Milenkovic are also on the Red Devils' radar according to reports, so it's clear defensive reinforcements will be made.

Antonio Valencia's seemingly imminent departure has added to speculation that new faces will be brought in.

Moving up the pitch, United are relatively strong in midfield with Paul Pogba, Nemanja Matic and Ander Herrera all rediscovering their form under Ole Gunnar Solskjaer.

Andreas Pereira seems to be making positive strides, too, after his stunning strike against Southampton over the weekend.

And then there's United's attacking options, of which they have many but could perhaps do with one more player amid doubts over Alexis Sanchez's future.

Sanchez - who was ruled out for two months on Monday with medial damage to his right knee - has been awful since joining from Arsenal 14 months ago.

The Telegraph's James Ducker claims "Sanchez's failure has reminded United of the perils of seeking short-term fixes", so they've made Jadon Sancho their number one target for this summer.

Sancho, 18, is one of Europe's highest-rated youngsters and could cost upwards of £100m. United's interest stems from changing their focus to the best young players.

Paris Saint-Germain are also interested but United are determined to sign the teenager so he can link up with other young talents like Marcus Rashford and Anthony Martial.

United landing Sancho would come as an embarrassing blow to rivals Manchester City, who failed to convince him to stay in 2017 when he joined Dortmund for £8m.

Sancho, Rashford and Martial leading the attacking line with Paul Pogba just behind them - now that's a scary prospect.