CELTIC’S problems in Europe go much deeper than their inability to defend but it seems a pretty good place to start. Barely a Europa League tie goes by these days without Ronny Deila’s side contributing rather spectacularly to their own downfall and here against Molde, a team sitting sixth in the Norwegian league, it was a similarly sorry tale. Should this Europa League campaign end with Celtic failing to make it out of Group A – and that looks fairly likely at this juncture – then they will come to lament a defence that, to borrow the Glasgow parlance, simply couldn’t keep weans out of a close.

The statistics are damning. One clean sheet in a dozen Europa League matches. No victory in the last nine games in that competition, with 20 goals lost in that time. They continue to score goals in Europe but it becomes rather more difficult when they also repeatedly ship plenty at the other end. If Deila thought he had been unfairly judged prior to this defeat, then the criticism will surely only now grow. The dissenting voices outside the Aker Stadium after the previous loss in Molde could perhaps be dismissed as the actions of a small, angry mob, but booing by the 30,000-odd here for the return match will be much harder to ignore.

Deila will be pained by yet more defensive lapses that blighted their performance like a big splodge of paint dribbling down a van Gogh. Celtic’s resistance on this occasion lasted just 21 minutes. It came as no real surprise to anyone inside Celtic Park that not only did they lose multiple goals – again – but that they were also complicit in their concession.

There is nothing that makes a football crowd more panicky than the knowledge that their defence is as reliable as a Volkswagen emissions test. And so every time Molde came within shooting distance of Craig Gordon’s goal there was more shrieking than at a Justin Bieber concert. It said a lot about the tension that one of the biggest cheers of the night came when Kieran Tierney broke up another Molde counter attack witsh the perfect sliding tackle. Here was a crowd grateful for small mercies.

Tierney, Celtic’s star performer, can be spared the inevitable inquest that will surely follow another defensive disaster. The rest may find themselves facing some difficult questions.

Tyler Blackett, in particular, looked repeatedly suspect, perhaps offering further evidence as to why Manchester United were happy for him to disappear on a season’s long loan. Subbed on after nine minutes, he would suffer the humiliating act of being taken off just an hour later, his place taken by Nir Bitton, hardly renowned as a central defender.

Bitton would fare little better in the role. He would last just seven minutes in defence before being shown a straight red card for pulling down Ola Kamara when it became obvious he was losing a footrace for the ball. He could have no complaints about the decision, although he could have been excused for offering a withering look in the direction of Tom Rogic for giving the ball away earlier in the move. “Great substitution”, one rather disenchanted Main Stand supporter shouted in the direction of Deila, the sarcasm in his applause not difficult to detect.

Dedryck Boyata, Blackett’s central defensive partner for most of the match, was only marginally more convincing - receiving a large ironic cheer when he successfully controlled a late ball forward - while even Mikael Lustig had his shaky moments, too. The defence could also make the case that those in front of them were hardly helping, Bitton twice in the first half needlessly conceding possession. It wasn’t a pretty picture.

The goals conceded were entirely avoidable. For Molde’s first, Blackett could only head Knut Olav Rindaroy’s hopeful cross straight into the path of Mohamed Elyounoussi. Boyata then decided on a “best wait and see” policy rather than closing down the forward, allowing Elyounoussi time to plant a terrific shot into the far corner.

The second was just as messy. Rogic couldn’t clear another hopeful thump into the box, was easily turned, deflected the cross to the back post where Daniel Hestad, a 40 year-old, was able to get ahead of Blackett to poke in the chance. And all this without Efe Ambrose – the usual fall guy – of the park.

By that point, neither was Jozo Simunovic. The big news pre-match was that the Croatian had been declared fit to play having seemingly recovered from an ankle injury. This would have come as a surprise to anyone arriving into the stadium five minutes late and seeing him sitting on the substitutes bench, having come off second-best in an early challenge.

It is still early days yet but there must already be concerns among some supporters regarding Simunovic’s injury-ravaged start to his time in Scotland. Clubs like Celtic do not spend an outlay of £5.5m on as player too often but when they do they expect to get value for money. Simunovic was going to be the figure around which a new defence could be constructed, a feat made rather more difficult when the player in question spends most of his time on the treatment table. Either he has been very unlucky or Dynamo Zagreb have sold them a pup. Celtic will be praying it his merely the former and he can yet prove a reliable and consistent performer. By goodness they could do with it.