Manchester United are expected to be very busy in the transfer market this summer.

The midfield will be the club's main priority, and United have already reached an agreement to sign Ederson from Atalanta, with an official announcement expected soon.

The Reds are also in talks to sign Mateus Fernandes from West Ham United, although the Hammers' asking price of around £80 million is likely to be a stumbling block.

United are also said to be interested in Bournemouth midfielder Alex Scott, while other targets such as Elliot Anderson and Sandro Tonali are seemingly out of reach, as things stand.

United are also keen on signing a left-sided defender. A new left-back is on the agenda, with Lewis Hall said to be the club's preferred target. A new left-sided centre-back could also arrive, with Micky van de Ven having been considered in recent months.

United are now said to be closing in on a deal to sign Castello Lukeba from Bundesliga club RB Leipzig.

According to Fussballdaten, United have identified Lukeba as a primary target this summer and are in pole position to secure the 23-year-old's signature, despite interest from Barcelona, Bayern Munich, Chelsea and Tottenham Hotspur.

United, along with Barcelona, have made contact with Lukeba's representatives to evaluate the potential cost of a transfer.

The report claims that Lukeba has a release clause of around £70-77 million, but intermediaries have informed interested clubs that Leipzig would be open to accepting a lower fee of around £51-56 million.

United need a top-quality centre-back if they want to win the Premier League next season.

Harry Maguire is a quality centre-back, but lacks mobility and is ageing. Ayden Heaven has shown a lot of promise, but is still very young. The same goes for Yoro, who is undoubtedly talented but still has a long way to go in his development, having struggled for form in recent times.

Matthijs de Ligt and Lisandro Martinez both have a handful of outstanding qualities, but also have major deficiencies in their games and concerning injury histories.

With Martinez's contract set to expire next year, United should look to sell. He is one of the best ball-playing centre-backs in the world, but has struggled to remain fit over the last few seasons and has weaknesses off the ball.

Should United sell Martinez, it would pave the way for the club to push ahead with their pursuit of Lukeba, or another marquee centre-back signing.