When you’re a club that has got as close to the Champions League as Juventus have over the past few seasons, and still fallen so agonisingly short, it’s difficult not to dwell on the little details; the initially innocuous-seeming individual moments that could have gone another way.

So what, then, is the reaction to massive errors like that of your new number one, Wojciech Szczesny?

What runs through the minds of their hierarchy, when they have recently been obsessively single-minded about aiming so high? This has never been a club for indulging errors and the prevailing feeling is that, just as Juventus have solved a problem at one end with the signing of a supreme, generationally-talented goalscorer like Cristiano Ronaldo, a different problem has suddenly presented itself in an inferior goalkeeper.

This is not to deny that Szczesny is a fundamentally good shot-stopper, or has significantly improved since his time at Arsenal.

Juventus vs Manchester United - player ratings Show all 22 1 /22 Juventus vs Manchester United - player ratings Juventus vs Manchester United - player ratings Wojciech Szczesny: 5 out of 10 Szczesny had very little to do for most of the game, but he flapped at the ball at the crucial moment for Manchester United’s winner. He did well to prevent Rashford extending the lead in stoppage time. REUTERS Juventus vs Manchester United - player ratings Mattia De Sciglio: 7 out of 10 A constant threat going forward on the right. Juventus were really unsettled defensively when De Sciglio was taken off. REUTERS Juventus vs Manchester United - player ratings Leonardo Bonucci: 7 out of 10 A quite magnificent pass over-the-top to set up Ronaldo. Solid defensively. AFP/Getty Images Juventus vs Manchester United - player ratings Giorgio Chiellini: 6 out of 10 Kept the visitors from producing many chances throughout the game. His team seemed to lose their cool after Mata’s free kick and he could have taken better hold of the situation defensively for the winner. AFP/Getty Images Juventus vs Manchester United - player ratings Alex Sandro: 6 out of 10 Not his most prominent performance. A few bright moments as an attacker. The own goal will go down as his, though the ball was heading in anyway. Getty Juventus vs Manchester United - player ratings Juan Cuadrado: 5 out of 10 Cuadrado might have been Juventus’ quietest individual when looking at the game as a whole, and he will rue his missed chance at 1-0. REUTERS Juventus vs Manchester United - player ratings Sami Khedira: 6 out of 10 Workmanlike and diligent on the left of the midfield three. Squandered one excellent opportunity. Getty Images Juventus vs Manchester United - player ratings Miralem Pjanic: 5 out of 10 Seemed strangely off kilter. His delivery was lacking for much of the evening. REUTERS Juventus vs Manchester United - player ratings Rodrigo Betancur: 7 out of 10 Very accomplished showing in midfield. Plenty of strong interventions and showed his range of passing. An emerging force. AP Juventus vs Manchester United - player ratings Paulo Dybala: 6 out of 10 Flashes of his considerable brilliance (his curling, dipping shot that struck the crossbar a notable one) but not as ultimately impactful as his team needed him to be. Getty Images Juventus vs Manchester United - player ratings Cristiano Ronaldo: 7 out of 10 One moment of magnificence that for a time looked to have decided the game. The volley was simply sublime. Tormented Luke Shaw at times with his fancy footwork, but otherwise drifted in and out of the game, as is his wont. AFP/Getty Images Juventus vs Manchester United - player ratings David De Gea: 7 out of 10 Two excellent saves from De Gea, one from a deflected cross and another from an edge-of-the-box curler soon after the hosts’ goal. He could do nothing about Ronaldo’s goal. Action Images via Reuters Juventus vs Manchester United - player ratings Ashley Young: 6 out of 10 Young struggled defensively at times but then produced a teasing delivery for the winner. Getty Images Juventus vs Manchester United - player ratings Chris Smalling: 6 out of 10 An average performance. Nothing of real note either positively or negatively. AFP/Getty Images Juventus vs Manchester United - player ratings Victor Lindelof: 6 out of 10 Lindelof will be disappointed that Ronaldo managed to get behind him, though both Bonucci’s ball and Ronaldo’s volley were magnificent. However, he made several crucial tackles and interventions during the rest of the game. REUTERS Juventus vs Manchester United - player ratings Luke Shaw: 6 out of 10 Many of Juventus’ brightest moments came down his channel, though Shaw was left a little isolated at times by Anthony Martial and Paul Pogba. AFP/Getty Images Juventus vs Manchester United - player ratings Ander Herrera: 6 out of 10 Added vital balance to the midfield. Typically combative, though on the night that wasn’t a bad thing. EPA Juventus vs Manchester United - player ratings Nemanja Matic: 6 out of 10 An early booking meant Matic had to be careful, but he was nonetheless strong in defensive midfield. He appeared to collapse off-the-ball in stoppage time, but seemed fine as the game came to an end. EPA Juventus vs Manchester United - player ratings Paul Pogba: 5 out of 10 Pogba was rather dire in the first half and not hugely improved in the second on his return to Turin, but popped up late on to help force the winner. He also won the free kick for the opener. REUTERS Juventus vs Manchester United - player ratings Jesse Lingard: 6 out of 10 Wasted one good counter-attacking opportunity in the early stages. A quiet affair for Lingard. REUTERS Juventus vs Manchester United - player ratings Ander Herrera: 6 out of 10 Added vital balance to the midfield. Typically combative, though on the night that wasn’t a bad thing. AFP/Getty Images Juventus vs Manchester United - player ratings Anthony Martial: 7 out of 10 Played from the left wing with Sanchez deployed through the middle. Worked relatively hard defensively and was composed in possession. Martial was a key catalyst in the comeback, taking the game to the Italians. His dribbling ability worried tired, aging legs, and one forward surge lead to the first goal. Getty Images

It’s just that he’s never going to be top class. And, when you’re a club like Juventus who are looking to make that final leap to the truly elite level, you have to maximise every possible area.

Szczesny, for all his virtues, will never do that. There’s always that lingering worry he has those game-changing moments, like that last-minute slip for Ashley Young’s free-kick, in him.

None of this can be said for the goalkeeper Juventus were facing, and who once again so drastically influenced the result for Manchester United.

David De Gea really is at the level where he is responsible for a disproportionate number of points for Jose Mourinho. He makes so many saves he really shouldn’t, setting his side up for draws and wins they really shouldn’t get.

Szczesny has improved immensely but remains a level below the elite keeper Juventus need (AFP/Getty Images) (Getty)

It is absolutely no exaggeration to say he is a Ronaldo of goalkeepers in that sense.

And his proposed new contract remains unsigned. It runs out in 2019, though United have the option of a one-year extension.

There has already been tentative interest from Juventus, and the feeling must be that a club as business-like as this will investigate the possibility of signing the Spaniard as his current deal runs down.

Part of the problem is that De Gea’s camp now actually recognise that value. While the feeling is that he really wants to stay, and is content at Old Trafford, there is a fair belief that he should be on Paul Pogba or Alexis Sanchez money. It’s hard to dispute.

Szczesny's back-up, Mattia Perin, remains highly rated by Juve (REUTERS)

Those who watch Serie A will greatly dispute that Szczesny is that much of a problem, and will talk up his performances there, but it is highly relevant that those around Juventus immediately talk up substitute Mattia Perin at the merest hint of an error.

The young Italian is highly rated, but there are some doubts about elements of his game, particularly his feet.

De Gea is a goalkeeper that eliminates doubt for his club. He’s just such a guarantee.

Juventus will have been reminded of the power of that on Wednesday. United too should have been reminded of it, and of the requirement to give their most important player what he deserves in the form of a new contract.

The contrast between the goalkeepers could not have been greater, and it made the difference on the night.