THESE things happen. It is a phrase which has been worn out by Celtic supporters over the last day or so as they attempt to come to terms with their team being given an almighty thrashing by Barcelona.

As one wag put it: “What time is the Celtic game kicking off? Every 10 minutes.”

Those more reflective supporters are quite right. In Glasgow parlance what happened on Tuesday in Catalonia can best be described as “wan o them”.

Except, and here’s the thing, losing 7-0 isn’t what Celtic do to anybody. Not that the team they were up against could be described as just anybody.

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The press box in the Nou Camp is not far from being attached to the very top level of that magnificent stadium and it afforded us hacks an eagle eyed view as Barcelona moved the ball around the pitch as if it were tied to an invisible string, and this correspondent is not convinced that it was not.

For those who love football, even the Celtic fans at home who must have started to find odd jobs to do about the house as the goals rained in, the performance by Barcelona was a joy to watch. We live in the era of Lionel Messi and when given space and time to do what he does better than anyone else, watching that wee man in the flesh is, I am guessing, akin to being in the same room when Michelangelo was sketching in his notebook.

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Genius is rare and must be admired. Messi can do things with his feet most mere mortals can only imagine pulling off.

Barcelona almost always win. Dominance can become boring and yet they do so with such elegance that nobody really minds that they normally finish on top. This does not happen often in sport. Only a few, Tiger Woods and Rodger Federer of modern times spring to mind, have been cheered on their way to successive wins because they do it in such style.

So Celtic should not beat themselves up about being beaten up by some of the best footballers of all time. But that does not mean the manager and his players escape any (mild) criticism after a 7-0 defeat, the record in Europe and just one goal, which could easily have come, of equalling being the heaviest of all time.

Rodgers’s Celtic career began with an embarrassing defeat, to part-time Lincoln Red Imps in Gibraltar, and has now taken in the heaviest loss in Europe. The good thing for the Irishman is that everything in between has been pretty impressive and it is clear he has a firm grip on the club which should mean the team will improve.

But in saying that Tuesday night would have been a difficult watch for Rodgers.

Celtic didn’t get close to making life difficult for the home side. Only Scott Brown put in any sort of firm challenge, off the ball to Ivan Rakitic, on a night when surely there was scope to at least get in the faces of the Barcelona team and let them know they were in a game.

In short, kick someone. I know that will offend the purists but occasionally such robust tactics are required.

Celtic’s players didn’t look so much shell-shocked as they did star struck. It was as if they didn’t want to go in hard on Neymar as if in admiration for what was happening in front of them.

By full time every last one wearing green and white just wanted off that pitch.

You could argue Rodgers should not have given a debut to Cristian Gamboa, who looked every inch a West Brom reserve in that company, while it was perhaps a night for Stuart Armstrong instead of Nir Bitton, as the Scot possesses tons of energy.

But such hindsight is close to useless. They wouldn’t have made any real difference, and that goes for Moussa Dembele’s missed penalty. If he scores it his team are still well beaten.

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Celtic are miles ahead of everyone else in Scotland and as far away, if not more, than the best of Europe and even those teams who operate in the two or three levels below.

There would have been Rangers fans who would have enjoyed their old pals getting turned over after they went down 5-1 last Saturday, a reminder of the days when the only joy for Celtic fans was watching Walter Smith’s side ship goals in Europe from the comfort of fourth place in the Premier League.

On Tuesday’s evidence, the best of our game can’t even see the football summit. What does that say for everyone else?

That’s the thing about the Champions League. When you get there all the talk is about the money it brings, the glamour it attracts and how it gives the supporters an opportunity to go on trips of a lifetime. Nobody mentions how bloody hard it is.