By

BBC Scotland's chief sports writer

To Celtic fans it might seem like sacrilege to doubt Martin O'Neill's capacity to get them through whatever it is they're going through right now - a slump or something deeper - but keeping the faith is surely becoming testing.

After their shellacking at Ibrox on Sunday, Celtic's response against Ferencvaros was another heavy defeat and three more goals conceded.

More absent-minded stuff in the midfield, more loose defending, more negativity and lack of accuracy on the ball, no great grasp of the basics of pass and move, not enough intensity, not enough work-rate, not enough of anything that you need to give yourself a chance.

At times, as it meandered along at 3-1 to Ferencvaros, Celtic tried to stage some kind of gallop but their attempts were from distance, hopeful efforts rather than anything built on the back of coherence and pressing and speed.

Celtic at their best - in the finest days under Ange Postecoglou - were all about aggression and ingenuity, about dynamism and risk-taking, about pace and belief and pulling defenders into places where they did not want to be.

This is a poor imitation.

O'Neill mirrors performance of his team

Things can turn quickly in Scottish football.

The second act of this season's Old Firm show on Sunday is still a hard one to call, partly because it's at Celtic Park and also because there surely has to be some kind of response from O'Neill's team to their pitiful fate at Ibrox last weekend.

Their fans will be worried, though. Five goals given up against LASK, a desperate experience at Ibrox - and now this.

In moments on Thursday, some of their football was reminiscent of darker days - the failures of Cluj and Copenhagen in 2019 and 2020, when Bayo and Bolingoli were in the building; Sparta Prague in 2020, when Klimala and Ajeti, Duffy and Laxalt were in the team.

It was all very Legia Warsaw, very Salzburg, very Maribor. The energy levels were low, the booing was loud and the feeling of a side with no answers was unmissable.

In the aftermath, O'Neill spoke about frustration, failure and psychological damage, how low moments like these hit you hard and test your resolve. He promised to "get ourselves together" for Rangers on Sunday but his tone was flat and a touch tired.

He outlined some of the ways in which Celtic were deficient on the night but didn't talk with the spirit of a man who had answers. In many ways his post-match comments mirrored his team's performance - leaden, stale, disheartening.

O'Neill has fixed many problems over the years, not just in his first trophy-laden spell but in his return to chaos last season. He restored order and confidence, two things that have been lost.

The force of his personality gave Celtic fight. They were not always pretty to watch but they were ferociously hard to beat. Nobody managed it on the title run-in.

That kind of never-say-die only seems like yesterday, but in other ways it feels like an awfully long time ago.

Celtic need solutions and inspiration

They had a decent start against Ferencvaros, then conceded a soft goal. They hauled themselves back into it with a little glimpse of quality, but then fell back into destructive ways. Safe passes, little zeal, only a modicum of fire and emotion.

The goal they conceded just before the break was the type of goal that poor sides give away. Hesitancy in the first instance to fight for the loose ball, weakness in the second instance when trying to prevent the cross and then defensive disorganisation and bewilderment in the end.

Celtic had 62.5% possession in the opening half but trailed 2-1. Camilo Duran, playing through the middle ahead of Kasper Hogh, had eight touches of the ball.

Duran was in his favoured position but offered little. A player who showed such zest and love of his new life in Glasgow only a few short weeks ago is looking a shadow of himself.

Hogh, with goals against Man City (two), Atletico Madrid, Inter Milan, Sporting, Porto, Jagiellonia and Olympiacos (three) for Bodo Glimt, has morphed into an awkward looking centre-forward with a poor first touch and no chances to feed on.

He has now scored in just one of his eight games as a Celtic player. O'Neill has so far failed to get the best out of a player the club paid £11m for.

Callum McGregor, the great totem, is looking a little lost. O'Neill has all the nous in the world to arrest this, but he needs to do it quickly. It has to be said, he doesn't look or sound all that convincing.

The way things are going for Celtic you could almost have guaranteed a goal for Daniel Arzani, their former player who came and went in a blur of nothingness.

To add salt, it was a magnificent strike after a counter-attack that exposed Celtic in the most embarrassing way. There was more order in the Keystone Cops.

Arzani appeared in acres of space on the left, Colby Donovan having over-committed to attack and now busting a gut in a forlorn attempt to recover. Arzani had patience and precision. He whipped his shot into the top corner. Easy.

O'Neill needs some amount of solutions in the coming days. Football is weird. He might find them, but his team is lacking ideas, conviction, composure, physical and psychological heft, creativity, ruthlessness and stomach for a fight.

The manager, himself, looks like he's lacking in any inspiration. He's bounced back from challenging situations in his football past and you almost become attuned to him doing so again, but there is a lot to fix here.

McGregor says the team is a little bit broken at the moment. Rangers might be licking their lips at the prospect of facing a wounded animal. Beware the backlash and all of that, but they have an opportunity to land another blow.

Sunday will tell us much about the way of things between the Glasgow giants.