Manchester United have looked like a shell of their former selves this season, despite continuing with Michael Carrick in charge. 

His side have picked up just six points in six Premier League games, while also exiting the Carabao Cup in the opening round against Brighton and Hove Albion. The Champions League has offered United fans some hope, though, with a 4-0 win in the first match against Sabah FK. 

United return to Europe this evening to face Atletico Madrid, with defensive concerns at the forefront of Michael Carrick's mind. 

Luke Shaw picked up an injury against Tottenham Hotspur and has not travelled to the Spanish capital, while Kobbie Mainoo has also remained in Manchester. With Shaw out injured, and Patrick Dorgu and Noussair Mazraoui also unavailable, Carrick will be forced to field a makeshift left-back. 

However, his former teammate, Paul Scholes, has claimed that it is central defence where there is a big issue. 

Manchester United's defence against Tottenham Hotspur was not impressive. Lisandro Martínez was bullied for the equaliser, Harry Maguire was poor throughout, and Luke Shaw was not seen for the opening half hour, and it seems Paul Scholes has seen enough from the central defence, at least. 

"Tottenham were bottom of the league ahead of the game on Saturday and they absolutely run all over Manchester United," he said on The Good, The Bad, and The Football Podcast. 

"We talk a lot about recruitment, don’t we? The idea is to make your team better and someone like [Manchester City summer signing] Elliot Anderson would make them better, but I’m not sure the players they brought in make them better.

"I actually think they’re alright in the forward areas but look at the centre-halves, that’s an area of the pitch that hasn’t been addressed for a number of years."

Scholes went on to say that he thought Manchester United would never be able to return to the top of the league, with Harry Maguire and Lisandro Martínez in central defence. 

"We’ve had the same centre-halves now for two or three years and we know you’re not going to be successful with them. You’re never, ever going to win the Premier League with them," he said. 

"The goal on Saturday was a prime example – we know Lisandro Martinez is a good footballer but for your centre-half to be bullied like that… you cannot let that happen, it’s criminal.

"Manchester United need a new back-four, they need a new back-four."

Many fans would agree with Paul Scholes, but if he is right, Manchester United will have to spend big to solve their issues. 

After an attacking rebuild in 2025, and a midfield rebuild in 2026, a defensive restructuring in 2027 seems likely. But how many defenders do Manchester United need? 

Ayden Heaven and Leny Yoro will both be hoping to remain at Old Trafford long-term, though neither of them are guaranteed to start, and Yoro has attracted interest from Paris Saint-Germain. Provided they both stay, that will be just two centre-backs United need if both Maguire and Martínez leave. 

At left-back, United have needed another option for some time. Luke Shaw is unable to play midweek and on weekends, but Patrick Dorgu is the only other option in that position, though some feel he is better suited further forward. With Shaw's deal expiring next summer, United could sign two left-backs. 

And as for right-back, Noussair Mazraoui and Diogo Dalot have both showed promise at times, but neither have looked good enough to win a Premier League. 

That leaves United potentially needing to sign five defenders next year.