By BBC Sport
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.