THERE have, despite the many crushing disappointments, been some signs this season that Celtic can accomplish things in Europe under Ange Postecoglou in future.

The win over AZ Alkmaar of the Netherlands at Parkhead in Europa League qualifying was polished and the start against Real Betis over in Spain in the opening Group G game was highly impressive.

So, too, were the home and away triumphs over Ferencvaros of Hungary while the narrow defeat at the hands of Bayer Leverkusen in Germany was harsh.

Postecoglou had, for all his experience at club and international level, never managed in continental competition before he moved to Scotland back in June. So to enjoy so many highlights with a team he had to put together in a short space of time is grounds for optimism.

But the Greek-Australian will need to revise his gameplan if Celtic are to compete in the Champions League group stages and challenge for a place in the knockout rounds – an achievement which his predecessors Gordon Strachan and Neil Lennon both savoured and which their supporters yearn to celebrate again.

The 5-1 aggregate defeat to Bodo/Glimt of Norway in the Conference League knockout round play-off – which was completed when they lost 2-0 in the second leg in Salten just north of the Arctic Circle last night – provided further evidence of that.

Kjetil Knutsen’s men have been a revelation in Europe this season. They beat Roma 6-1 at the Aspmyra Stadium, drew 2-2 with the Italian giants in the Olympic Stadium and went undefeated in Group C. Do not bet against them progressing to the quarter-finals or even further.

Still, Celtic could and should have done far, far better and Postecoglou must shoulder his share of the responsibility for the latest failure.

He had stated before the first leg that his objective was to win the new competition. It was an admirable declaration of intent. But that looks an awfully long way off at the present moment in time. 

His team were vulnerable defensively, failed to gain a foothold in midfield and lacked a cutting edge up front in both Bodo games. Any weakness is cruelly exploited against foreign rivals, even by those from lesser football nations. So they could have no complaints about being soundly thrashed.

Postecoglou is committed to his team playing attractive and flamboyant football regardless of who they are facing or where. When it has worked well they have romped to some emphatic wins and delighted their fans. When it hasn’t? Not so much. Taking a more cautious, less gung-ho approach would be well advised.

Brendan Rodgers steadfastly refused to ask the likes of Mikael Lustig, Scott Sinclair and Kieran Tierney to curb their natural attacking instincts whenever they played in Europe during his two-and-a-bit years in charge in the East End. Again, that was laudable. But it was also naïve.

It led to some heavy defeats at the hands of Barcelona, Paris Saint-Germain, Bayern Munich and Zenit St Petersburg. They are massive clubs with huge budgets admittedly. But those results were still humiliating.

Such embarrassments await Celtic again unless there is a change in their manager’s tactics.

Johan Mjallby, who helped Martin O’Neill’s celebrated side reach the UEFA Cup final back in 2003, is optimistic that Postecoglou has learned invaluable lessons since joining from Yokohama F Marinos in Japan in the summer.    

“The manager has found out that you need to find the right balance in Europe,” he told BT Sport last night. “I really, really enjoy watching Celtic with their expansive football going forward. It’s impressive. But in Europe if you leave gaps, if you leave space, you get punished.”

If you know your history, you would have been aware that Celtic had never overhauled a two goal deficit in Europe away before last night. They had staged comebacks against St Etienne, Sporting Lisbon, Cologne and Shakhter Karagandy at home on the past. But on their travels the feat had proved beyond them.

However, Postecoglou has to take the blame for the fact that the former European Cup winners were playing catch-up against Bodo in the first place. His team selection seven days earlier had played into the visitors’ hands. Deploying Matt O’Riley and Tom Rogic alongside Callum McGregor in midfield was rash and left his skipper exposed.

He clearly chose his starting line-up last night with one eye on the cinch Premiership encounter with Hibernian at Easter Road at noon on Sunday. That Liam Scales, Anthony Ralston, Nir Bitton, Stephen Welsh and James Forrest were brought in was understandable to an extent.

The Scottish title race is tight and any slip-up could prove costly. Having key personnel fit and fresh this weekend could ensure that another three points are picked up and the lead over Rangers at the top of the table is maintained, possibly even extended.

Celtic, though, are expected to do well at home and abroad every season. This term they have exited the Champions League, Europa League and Conference League. Allowances must be made given the major rebuilding job that Postecoglou had to oversee after succeeding Lennon.  It could be argued he has overachieved.

That said, he has had nearly £25m to spend on no fewer than 19 new players. He will have to make far more of an impact in Europe in the 2022/23 season or supporters will not be nearly so understanding. A radical rethink could help him realise heady ambitions.