And relax. Arsenal’s season, so vital up to Christmas, has been rasping away on its gurney for a month or so now, tubes rattling, monitors beeping. At the Camp Nou it was finally euthanised into submission in a lively fun, low-pressure 3-1 defeat by the world club champions.

Not that Arsenal’s season is really dead, of course. They can at least collapse now into the comforting embrace of that late-season battle for a little more of the same old. Hello fourth place, my old friend. I’ve come to fight for you again.

In fact, there was a sense throughout here of echoes, patterns, deja vu all over again. By the time Mohamed Elneny had scored a sensational equalising goal in the 51st minute this was already shaping up as another lively, pointless face-saving exercise, evidence of the quality in the team that so frustrates; but which was always likely to fall short over 180 minutes against one of the great club teams.

Luis Suárez acrobatics end Arsenal’s unlikely resistance at Barcelona Read more

On a horribly wet night this steeply-banked concrete mega-bowl was a bedraggled spectacle, disturbed for long periods only by the odd stirring of dutiful enthusiasm. And really this was a game that told us nothing about anything much. There were some sparks. Alex Iwobi can certainly come again. Wenger had given Arsenal a 5% chance of progressing, chances not improved by the selection of a breezy, fun-looking League Cup tie team. Iwobi made his full Premier League debut this year. Six of the 12 games in which he has featured have now been lost, including a 5-1, a 4-0 and a 3-0. Way to blood the kids, gaffer.

But Iwobi was good. He looked like he’d come to play. He has a strut, an amble, a nice weight of pass that is actually quite suited to this kind of game. In the first half he tried to nutmeg Andrés Iniesta. He wall-passed his way around Lionel Messi in his own half, a moment to cheer even the most jaded, sodden travelling soul.

Shortly afterwards Iniesta floated the most divine diagonal pass on to Messi’s toe inside the area, a pass to celebrate, capture in song, tell long, wistful stories about around the campfire. Moments later, like a man finally giving up on the snooze button and dragging himself out from under the duvet, Barcelona opened the scoring, Neymar prodding home from Luis Suárez’s pass.

For a while after there was a vague fear this might turn into a genuinely bad night for Arsenal. Barcelona don’t really do going through the motions. The motions here are simply to score as many as possible. Not that the odd thrashing has ever been the problem. This is a club where disappointment comes in fine, pungent shades. Much worse are the might-have-beens, those occasions when victory only seems to become an option when it is no longer an option. For example, the 2011 Champions League second leg here when Nicklas Bendtner spurned the chance to knock Barcelona out (the real detail, perhaps, the fact it was Bendtner doing the spurning). Monaco. Bayern Munich twice. So near, yet so never actually anywhere near.

For a while this looked like a might-have-been in the making. Barcelona enjoyed themselves. Ivan Rakitic rolled his foot over the ball, skipping away twice from Mathieu Flamini like a boy teasing a game old dog. Soon after Flamini was booked for hurling his entire frame at a running jump into the back of Javier Mascherano. Yep. Probably a foul, that one.

But Arsenal had chances and played well before Suárez scored a stunning Barcelona second, a flying Di Canio-style volley that bulged the far top corner and briefly sucked the air out of the stadium.

And that was pretty much that, for Arsenal a fourth – and oddly routine – exit from this competition at the hands of these opponents. It isn’t hard to see why Barcelona like playing Arsenal. There isn’t a great deal to fear when you are essentially playing an own-brand supermarket version of yourself. Arsenal’s strengths – ball retention, quick passing, neat midfielders – are a kind of homage to that hyper-modern template. But expecting them to beat Barcelona regularly is a bit like expecting Shakin’ Stevens to come out and blow Elvis off the stage.

What seems certain is that when Wenger does finally retire this club will haunt his dreams, the fond big brother who keeps you at arm’s length while absent-mindedly pummelling you with the other hand. Since 2000 Barcelona have spent £123m on eight Arsenal players, enough, as the Daily Mail pointed out last year, to finance a third of the construction costs of the Emirates Stadium.

For all that, defeat here isn’t the kiss of death some would like. Arsenal’s season may be over, but Wenger isn’t quite yet, for all the gathering sense of endings. Assessing Arsène: it isn’t easy. It requires both a long and short view, an impartial eye and the ability to judge against other, parallel, non-Arsène timelines.

In a reverse of the usual scenario, the wider structures at Arsenal are settled and healthy, credit to Wenger’s de facto dual role as manager-director. It is the detail that falls short, fine points of selection, tactics, mentality, the sharpest points of the machine. Arsenal’s fans will have left the Camp Nou happy at this performance, but still divided, and indeed genuinely puzzled, by a club that dallies and dithers and drifts with such grace.