Manchester United are entering another crucial period under Ruben Amorim. After signing just two players in the January transfer window, the Red Devils are still short.

Patrick Dorgu's arrival from Lecce strengthened Amorim's options at wing-back and Ayden Heaven became the latest exciting prospect to move to the club.

United now have the tough task of rescuing their season. Hopes of retaining their spot in European football is likely to be determined by their success in the FA Cup and Europa League with them lurking in the Premier League bottom-half places.

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Should the worst-case happen and United have no European football to play - resulting in the loss of millions - then Sir Jim Ratcliffe and Amorim will once again be restricted to what they are able to do in the summer despite the alarm bells ringing.

A new striker is expected to be at the top of United's transfer list at the end of the season with a new midfielder also likely to be considered amid uncertainty over Casemiro's future and Christian Eriksen's contract expiring.

However, centre-backs are vital in the Portuguese's formation with Lisandro Martinez, Leny Yoro and Matthijs de Ligt all impressing at stages. Harry Maguire has also filled in when required but there's a feeling that United's backline lacks a real colossal.

The top teams in Europe all have world-class options in their defence. Virgil van Dijk continues to be key to Liverpool, Antonio Rudiger and Eder Militao patrol Real Madrid's defence and Arsenal's partnership of William Saliba and Gabriel Magalhaes is widely-regarded as the best in Europe.

Yoro has the potential to become that world-class figure in United's defence in the future. De Ligt has won titles everywhere he goes and Martinez, barring his injury concerns, has been a consistent player since signing.

However, the rumour mill is gearing-up ahead of the summer and two central defenders have been linked with strengthening Amorim's defence. AFC Bournemouth's Dean Huijsen, who has a £55millon release clause, and RB Leipzig's Castello Lukeba are both on the Red Devils' radar.

Alongside Chelsea, United are thought to be considering a move for Huijsen after his sensational breakthrough season in the Premier League. Caught Offside claim that Tottenham, Bayern Munich, Real Madrid, Barcelona and PSG are all keeping tabs on the 19-year-old.

Lukeba would be more expensive, in regards to his release clause, with that figure sitting at £75m. The former Lyon star has impressed in Germany and Sport BILD have claimed his entourage are preparing for a big transfer in the summer.

Either player would improve United's defence. Victor Lindelof is set to depart at the end of his contract and three-man defence requires quality. The summer transfer window may be an important one for attacking reinforcements but the defence could also endure a shake-up.