A hugely disappointing night for Celtic ended their hopes of qualification for the Champions League at the same hurdle as last season, going out 5-4 on aggregate to Cluj after a 4-3 defeat on the evening.

Goals from James Forrest, Odsonne Edouard and Ryan Christie weren't enough to avoid dropping into the Europa League. Here are five talking points from a crazy night at Celtic Park...

MOVING CALLUM MCGREGOR TO LEFT-BACK WAS A HUGE MISTAKE

Neil Lennon threw a curveball with his line-up, removing Boli Bolingoli from the firing line and shoehorning McGregor in at left-back, with Olivier Ntcham and Scott Brown in the centre of the park. That was the same set-up that flopped miserably at Ibrox as Celtic were defeated by Rangers under Brendan Rodgers in December, and there was little sign of the approach working any better here.

The midfielder looked uncomfortable from the off, getting caught under a looping cross that Deac failed to make a proper connection with.

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The uncertainty in the backline was exemplified though as another swinger from Billel Omrani to the back stick saw Deac rise to connect with his head this time and find the net via the inside of the post to put Cluj ahead.

McGregor coped a little better after the interval and put his stamp on the game going forward, but he was still susceptible to the long diagonal to Deac, who was found on numerous occasions to dangerous effect.

CELTIC STRUGGLED AGAINST THE HIGH PRESS

Another disruptive influence on Celtic was their inability to cope with the high press adopted by the visitors, who weren’t afraid to employ the dark arts too whenever the hosts looked like breaking free.

Striker Mario Rondon in particular was skirting on the edge of the laws of the game all evening and was withdrawn at the interval to save him from a dismissal.

Celtic got out more in the second half, but they were never at their free-flowing best throughout the evening, and the visitors have to take a huge portion of the credit for that through their tireless work-rate in pressuring their opponents.

SCOTT BROWN’S MOMENT OF MADNESS COST CELTIC DEAR

Just as the tie was swinging Celtic’s way, their captain of all people let the side down big-time.

A Cluj corner to the back post looked to be drifting to safety, but Brown spotted a visiting player sneaking around the back and instinctively threw up a hand to divert the ball away. Straight away, his body language told you everything you needed to know, with referee Andris Treimanis pointing straight to the spot.

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Perhaps he was due a favour from his teammates after countless inspirational showings down the years, but while it wasn’t the defining moment in a topsy-turvy evening at Celtic Park, they couldn’t ultimately dig him out of a hole.

IF YOU LOSE FOUR GOALS AT HOME, YOU HAVE NO EXCUSES

Celtic’s sluggish start here cost them dear too. Going into the break a goal behind forced their hand, and while their gung-ho approach in the second half yielded three goals, it also left the door open at the back.

True, there was no legislating for Brown’s moment of madness that cost his side a penalty, but the third goal for the visitors was also avoidable, Deac being given far too much space to get a shot away that Scott Bain could only parry out to Omrani to get the all-important third goal of the night for the visitors.

The goal from substitute George Tucudean with the last kick of the ball that put the tin lid on a night of huge disappointment for Celtic was a case in point, as a simple ball over the top set him in on Bain with the hosts forced to leave themselves hugely short at the back.

A COSTLY NIGHT FOR CELTIC, IN MORE WAYS THAN ONE

While money would not have been at the forefront of Lennon and his players’ minds during or immediately after this match, there is no doubt that the potential £30m or so that Celtic have now missed out on will have a knock-on effect down the line.

Yes, they have just pocketed £25m for the sale of Kieran Tierney, but with neither of the players who Lennon spent a combined £10m on this summer already not trusted to play here in the shape of Bolingoli and Christopher Jullien, it will be interesting to see just how much more cash he is allowed to play with in the remainder of this window.