The veteran boss still doesn't know his strongest line up amid a rollercoaster campaign

There were a couple of moments on Thursday night that pretty much sum up where Celtic are right now.

And both involved Haissem Hassan.

One of them was thrilling. The Egyptian wide-man picked up the ball deep in his own half, realised he only had one man to beat and skinned him with ease, charging up the touchline on a 70-yard run to win his side a corner. Celtic Park roared in appreciation.

But then there was the flip side. In the first 20 minutes against Celta Vigo, the Spaniards hogged the ball like a spoiled child.

They passed and probed but a lot of the space was down Celtic’s right side.

Hassan wasn’t interested. He was sauntering around on the flank, oblivious to the fact that runners were targeting that area.

Teenager Colby Donovan was roaring at his team-mate, begging for hauners. It never came.

While Hassan was a threat at times, it was his side that led to Celtic’s downfall as they slumped to yet another mortifying European defeat.

And there it is. Celtic have players who can be dangerous going forward – but they are utterly hopeless when it comes to defending. Hassan sums it up – but he’s not the only one.

Benjamin Nygren is no doubt a player and carries an incredible goal threat.

But he’s very much from the Tom Rogic school rather than the Stuart Armstrong approach.

When Celtic don’t have the ball, the Swede is a man down.

Mika Baur puts in a shift and does try to press and tackle, even if he’d struggle to beat the height restrictions at the Time Capsule flumes.

But the German’s keenness to get into positions to support his side going forward also causes a problem.

If he doesn’t get the pass, he can get stranded in wide areas or further up the pitch – leaving Callum McGregor facing the Alamo.

All this means Celtic are carrying luxuries that should shine most weeks against teams who don’t have the quality to punish them. But it leaves them wide open to suffer when they come up against a higher level of opposition.

It’s a conundrum Martin O’Neill has struggled to solve given he was dealt a snide hand in the transfer window – but it might have to come from the players themselves.

There was a brilliant quote that popped up last week from Jurgen Klopp: “As long as you are not Messi, you must defend for me.”

The wee Argentina superstar might get a pass when it comes to graft but no one else does.

Hassan might think he’s Messi at times, but he’s not. So shirking off and leaving a teenage full-back exposed simply is not on.

That’s the gig at Celtic. There will be times when you can go on the tear against some domestic rivals on a fraction of your wages.

But when it comes to facing more level playing fields, you need to put in a shift.

Too many at Celtic don’t seem to realise it right now – and it’s not reflecting well on the manager.

Hoops fans will go after the board after nights like Thursday as the bigger picture stuff comes into play.

It’s all fair game. Celtic’s embarrassing European mishaps are down to more than just the man in the dugout.

But O’Neill has to carry the can when his side are conceding 20 shots a game and going to bits whenever the pressure is turned up.

Five defeats in seven games is Nancy territory. The fact the defeats haven’t mostly come in the league has probably spared O’Neill from further criticism.

But there will be times when domestic teams make Celts pay for being so easy to play against – unless the luxuries like Hassan get their sleeves rolled up.