This Manchester United team cannot consider itself anywhere near Europe's elite and the freakish events that saw United claw back a 2-0 home loss to overcome Paris St-Germain in the last 16 rarely strike twice.

No doubt we will hear about that incredible night in Paris, how seemingly insurmountable mountains can be climbed and how it is 20 years since United's only win in the Nou Camp - the dramatic 1999 Champions League final win against Bayern Munich.

There might even be a mention for the Champions League semi-final against Juventus in Turin that same year when United came from two goals down to win 3-2.

It is a romantic narrative but Barcelona deal in reality. With United 1-0 down, it would be truly astonishing if Ole Gunnar Solskjaer's side came through next Tuesday's quarter-final second leg to reach the last four where, in all likelihood, Liverpool would await.

Barcelona have not lost at home in this competition for six years and the harsh reality is that they were, by their own standards, decidedly average at Old Trafford but won without any anxiety. Manchester United did not have a shot on target in a Champions League game for the first time since March 2005, when they lost away to AC Milan.

It was a workmanlike Barcelona but they still eased through.

The business of making proclamations about the second leg is a hazardous one, given how United somehow navigated themselves out of the tightest corner in Paris.

United's biggest problem is that they lack the quality and creativity to have anything more than blind hope when they travel to Catalonia.

The last time Barcelona lost a tie in this competition after winning the first leg was in 1984. Not many would bet against that changing when United arrive at the Nou Camp.

Straws will be clutched at and chances will be talked up, as they should be because Solskjaer and his players must believe. But in reality, no logic or form says United can escape this time.

Barcelona's players, particularly Luis Suarez and Lionel Messi, were pictures of disappointment as they came off at Old Trafford, despite a crucial win that took them to the brink of the Champions League semi-final.

While goalkeeper Marc-Andre ter Stegen effectively had the night off, Barcelona created the better chances - even through they were not at their best. David de Gea saved with his legs from Philippe Coutinho and Messi, while Suarez was uncharacteristically wasteful when through on an angle.

The plus point for United is that they only trail by one goal, a better outcome than Old Trafford feared when Suarez's 12th-minute header was deflected in by Luke Shaw and confirmed by VAR after initially being ruled offside.

And, in the context of this game, the biggest plus of all was the performance of 22-year-old Scott McTominay, who showed great maturity and composure in a Champions League quarter-final surrounded by a galaxy of stars.

McTominay was top class, overshadowing his £89m midfield partner Paul Pogba and looking completely at home throughout.

He was United's best performer and this was confirmation, if it were needed given how highly he is rated inside Old Trafford, that he can be trusted in high-pressure situations and in the most illustrious of company.

McTominay's display was certainly in contrast to Ashley Young, who had a dreadful night, especially when it came to the crucial area of delivery from wide areas.

Fred also gave a respectable showing but the most ominous statistic of all was the shortage of shots on target, a fair reflection of the impact (or lack of) made by the substituted Romelu Lukaku, Marcus Rashford and latterly Anthony Martial.

It is something they must change in the Nou Camp and there have to be doubts about whether this current United side, which will require widespread refurbishment at the end of the season, has it within itself to accomplish the task.

And that is before we even consider the very real likelihood that Barcelona at home will produce a vast improvement on the scratchy, careless performance they produced here.

Messi was relatively quiet, some of the passing was strangely lacklustre and yet the suspicion remains that this was Barcelona playing within themselves, while Manchester United produced the best they could.

This made it four defeats in five for Solskjaer as he now settles permanently into the Manchester United manager's office.

His players must overturn form, logic and the history books in the Nou Camp.

Manchester United may have done it once - it is very hard to see them doing it again.