There were 24 minutes remaining when Michael Carrick finally decided to put Diogo Dalot out of his misery and a huge chorus of mock cheers erupted around Old Trafford.

By the time Dalot had jogged to the touchline, those cheers had turned to jeers as Manchester United fans rounded on a full back who, for many, has become an emblem of the survival culture that has been allowed to take root for far too long, especially where the defence is concerned.

There were shades here of the reaction to Joshua Zirkzee’s first-half substitution against Newcastle in December 2024, and it was perhaps fitting that the Dutchman appeared to console Dalot before the defender took his seat on the bench.

Having been slow to close down Alysson’s shot for Aston Villa’s first goal, Dalot then gave away the penalty for the third after tripping the Brazilian, who gave him the runaround all afternoon only five days after a similarly haphazard defensive display against Roma in midweek.

There are plenty of fans who will disapprove of a player being subjected to such treatment, regardless of how poorly he may be playing, and Carrick jumped to Dalot’s defence afterwards.

That was certainly the case with Zirkzee, who received an outpouring of support in the days and weeks that followed his humiliating episode.

But it was also a stark reflection of the acute frustration among the United fans who foresaw so many of the individual and collective defensive problems that have plagued Carrick’s utterly chaotic side this season.

United have now shipped 15 goals in five games, with Sunday’s wild 4-4 draw against Villa full of the kind of alarming concentration lapses and feeble individual moments that have become commonplace this term. The side also continue to start matches so appallingly.

Frankenstein defence not fit for purpose

A degree of bewilderment continues to surround the way United have set about rebuilding the squad over the past two years, with first the attack and then the midfield revamped at the expense of any defensive reinforcements.

But how did anyone think a defence full of players who are seldom available, raw and unproven or, more damningly, have failed under so many previous managers, would be good enough this season with another top-four finish the target and Champions League football to negotiate?

Would a more balanced approach, rather than the block-by-block method that put the defensive overhaul on the back burner until summer 2027, not have been a wiser strategy over the previous couple of summers, with only so much money to go around and problems all over the pitch?

Dalot was signed in 2018 by José Mourinho and seems to have survived this long by virtue of the club having bigger problems to address when each summer comes around.

But the same applies to so many other defenders – Luke Shaw, Harry Maguire, Lisandro Martínez and Matthijs de Ligt among them – so it becomes hard to view things in isolation. This Frankenstein defence has long not been fit for purpose.

Shaw, signed in 2014 by Louis van Gaal, defied most expectations by starting every Premier League game last season yet United went into the campaign with the injury plagued 31-year-old as their only senior recognised left-back.

Unsurprisingly, he has barely been available – he has played one game in seven weeks – and that has often meant playing the likes of Dalot, a player who has struggled enough in his preferred right-back slot down the years, as a makeshift left-back.

Dalot’s biggest attribute has been his perennial availability among a squad routinely missing defenders through injury and ill-discipline.

Martínez, who has started just 72 of United’s 162 Premier League games since arriving from Ajax for an eye-watering £57m in 2022, was suspended against Villa following his red card in the 2-0 defeat at Chelsea. If he is not injured – and he often is – the Argentine liability finds other ways to make himself unavailable.

Maguire lasted 45 minutes here before being substituted with a back spasm. Signed by Ole Gunnar Solskjaer in 2019, the centre-back has had so many ups and downs at Old Trafford but, now 33, is really starting to look his age.

Noussair Mazraoui is a squad player at absolute best. And what about another signing from Bayern Munich, the lesser spotted De Ligt? He has played 81 minutes since injuring his back 12 months ago and was an unused substitute against Villa, his fitness clearly still an issue.

As for Leny Yoro and Ayden Heaven, both 20, this would be a very difficult environment for any young defender.

United could well need three new centre-backs and two new full-backs as a minimum next summer.

How could the club have left themselves in a position of needing to do such major surgery to the back line in one go? Agents and other clubs will see them coming a mile off.

By then, it could be too late anyway because, if they miss out on Champions League football, they will be back in that vicious circle and again facing the added financial pressures that come with that.