The three certainties of life as a Celtic fan: death, taxes and European goals gifted with abandon.

That this was a performance coupled with attacking verve and nous with a glut of players sitting on the treatment table will only enhance the sense of frustration as Celtic touch back down in Lennoxtown this morning.

To score three goals on the road in Seville, to be 2-0 up – should and could have been 3-0 – and still leave empty-handed underlines the lack of composure and defensive cohesion at this level.

It also means that Celtic’s travel sickness continues. Spain has never been a happy hunting ground as the clock ticks over now to 20 performances without a win.

READ MORE: Detailed Celtic player ratings as Tom Rogic and Jota shine in seven-goal thriller against Real Betis

Like so many European games before, this was within grasp. There is a long list of Celtic being caught cold and shipping not just one cheap goal but another immediately at its back as points disappear in the rearview mirror; Salzburg, Fenerbahce, Hapoel, PSG, Barcelona, Molde…'s a new cast but an old movie.

And while much will be made of Ange Postecoglou’s philosophy and a certain rigidness when it comes to the way he wants his team to play, the key point against Real Betis was the individual errors that proved to be so costly. His style and methodology spooked the Spaniards for the first half hour before the perennial defensive frailties were exposed.

Ultimately there may be an argument for a more pragmatic approach for certain stages but personnel to a large degree forced his hand in Seville.

In truth, few would have expected to leave unscathed from their opening game in the group given the lack of key players but, still, to be so close and to leave with little to show for it will rankle. Callum McGregor’s loss was crucial while the movement of Kyogo Furuhashi was always going to be missed.

READ MORE: Celtic go down fighting amid 'Angeball' in all its splendour and glory - Tony Haggerty

Albian Ajeti is a lurker inside the penalty box but doesn’t have the same ability to link up play that the little Japanese internationalist does. He’ll be quietly satisfied with his own stats, right enough, that now boast three goals from his last two outings.

The real difficulty, though, for Postecoglou isn’t remaining married to the principles that underlined his Celtic honeymoon but getting a settled team to live out those vows.

There were just three survivors last night from the team who went out of the Champions League to Midtjylland seven weeks ago. There has been a need to bring in a raft of new players and force them straight into the starting line-up with varying degrees of success.

Injury issues were a headache last night but of the back four who started against Betis, three out of four would be considered regular picks.

The Greek-Australian will hope for a stable hand when the treatment room starts to clear but he will also look for a level of consistency defensively that hasn’t been there yet.