It has become a ceiling on Manchester United's ambitions. When the ball arrives at Aaron Wan-Bissaka's feet in the final third you can almost hear the collective groan around Old Trafford.
Roy Keane recently quipped that Crystal Palace would be reluctant to take Wan-Bissaka back after sanctioning his £50m sale to United in 2019. It was a cheap dig, but the point remains that it's difficult to envisage another top club entertaining the idea of signing the former Palace full-back.
Enter, Diogo Dalot.
With Wan-Bissaka missing from the squad against Arsenal on Thursday night, the Portuguese was drafted in for his first league start of the season. As incoming boss Ralf Rangnick watched on from the stands, he certainly gave the the German cause for optimism.
His involvement in United's second goal - and Cristiano Ronaldo's 800th - was particularly noteworthy. With Arsenal left back Nuno Tavares out of position, Dalot showed the speed of thought to execute a gorgeous reverse pass into Marcus Rashford in space. The Englishman then pulled the ball back to Ronaldo with his next action to sweep United in front.
It is those moments of ingenuity which Wan-Bissaka has often lacked. His defensive minerals have never been questioned - note the number of last-ditch blocks in which he's responsible for - but United have suffered from his lack of conviction in the final third. The ball has essentially been left to rot whenever they switched play out to the right flank.
United fans could only look on in envy as Trent Alexander-Arnold and Andrew Robertson powered Liverpool to the Premier League title in 2019/20. The former's creative numbers have completely dwarfed those of Wan-Bissaka's and, to put it kindly, it can often appear that they're playing a completely different sport.
Chelsea under Thomas Tuchel have also underlined the value of full-backs with consistent end product. Reece James sits atop the Blues' top scorer charts this season - five goals and five assists - while Ben Chilwell had been in top attacking form until his recent injury.
Rangnick will also be encouraged by left-back Alex Telles, whose omission under Ole Gunnar Solskjaer this season left the United faithful scratching their heads amid Luke Shaw's loss of form.
The Brazilian has largely impressed in a United shirt, but his inability to string a run of starts together has undermined his effectiveness. The full-back competed well against the dangerous Gabriel Martinelli, with his athleticism a key component against a winger with searing speed.
There are still gaping holes in this United team, and it's correct to point out that the full-back positions are secondary to the absence of quality in the heart of the pitch. But it is an area which was neglected under Solskjaer and will require immediate surgery under the incoming manager.
But, at long last, United finally have a combination of full-backs who can meet the demands of modern, high-octane football. In that regard, Rangnick can start work in Manchester with a smile.
Source : 90min