Manchester United are widely expected to bring a new central defender to the club during this summer's transfer window.

Harry Maguire, Raphael Varane and Victor Lindelof are all likely to remain with the Red Devils for the 2022-23 campaign, but Phil Jones, Eric Bailly and Axel Tuanzebe could all depart.

Man United conceded 57 Premier League goals during the 2021-22 season, and new head coach Erik ten Hag has seemingly identified the defence as an area in need of strengthening this summer.

With that in mind, Sports Mole picks out five players that the 20-time English champions could target in the upcoming market to boost their backline.

Pau Torres (Villarreal)

Pau Torres is believed to be Man United's leading centre-back target this summer, with incoming manager Ten Hag said to be determined to sign the Spain international.

The 25-year-old, who is said to have a release clause in the region of £55m, made 47 appearances for the Yellow Submarine last term, playing a key role in the team reaching the semi-finals of the Champions League.

Torres recently said that he was "very calm" amid the speculation surrounding his future, but it is difficult to imagine him remaining at Villarreal beyond the end of the summer transfer window.

Now a key player for Spain, the centre-back could grow into a leading player for Man United in the coming years, but a number of other clubs are said to be also keen to secure his services ahead of next term, which is not a surprise considering his performances over the last couple of years.

Jurrien Timber (Ajax)

Jurrien Timber starred under Ten Hag at Ajax last term, making 43 appearances in all competitions, scoring three goals and providing two assists in the process.

The Netherlands international impressed in the Champions League during the 2021-22 campaign, making eight appearances, and the fact that he is also capable of playing right-back makes him an attractive proposition for the 20-time English champions.

Timber would likely cost Man United in the region of £30m, which makes him an ideal signing, as the Red Devils want to bring a number of new players to the club this summer as part of a rebuild, and there are not unlimited finances following their failure to qualify for next season's Champions League.

The 20-time English champions would be signing potential rather than the finished article, but he is certainly capable of developing into a top defender in the years to come.

Lisandro Martinez (Ajax)

Lisandro Martinez has also been strongly linked with Man United in recent weeks, with the 24-year-old impressing under Ten Hag in Amsterdam during the 2021-22 campaign.

The Argentina international featured on 37 occasions last term, including eight outings in the Champions League, but he still has more than three years left to run on his contract at Ajax and would be more expensive than Timber, as he is more established at the top level.

Martinez is a left-footed centre-back, which is also believed to make him attractive to Ten Hag, while he has been part of a successful side at Ajax, winning two league titles and one Dutch Cup since arriving in 2019, so he knows what it takes to win trophies at the top level.

Barcelona have also recently been credited with an interest, though, and there might be a battle for his signature if the Dutch outfit signal that they are open to offers.

Alessandro Bastoni (Inter Milan)

Alessandro Bastoni was again a vital player for Inter during the 2021-22 campaign, making 44 appearances in all competitions, including 31 outings in Serie A.

The Italy international - also strongly linked with Tottenham Hotspur - only has two years left to run on his current deal, though, which could lead to him moving on in the upcoming market.

Bastoni came through the youth system at Atalanta BC before joining Inter in 2018, and he has turned out for the San Siro giants on 117 occasions, winning Serie A and the Coppa Italia.

The 23-year-old has now had three straight seasons of regular football in Serie A, and the centre-back is said to be open to making the move to the Premier League in the upcoming market.

Kalidou Koulibaly (Napoli)

Not too long ago, Napoli are believed to have valued Kalidou Koulibaly in the region of £100m, but the 30-year-old's price tag has now allegedly dropped to £30m, with his contract due to expire in June 2023.

Koulibaly was again a vital player for his Italian club in 2021-22, making 34 appearances in all competitions, and a host of clubs are believed to be interested in his signature.

The Senegal international is said to be wanted by Barcelona, Juventus and Inter Milan, but his agent has denied that there have been any talks this summer over an exit.

Man United have long been credited with an interest in the powerful centre-back, who would not be a long-term option, rather a player capable of coming in for a few seasons and having a big impact.

Koulibaly certainly has the stature to be a force in the Premier League, and his contract situation in Naples means that there is a bargain to be had in the upcoming market.