THIS utterly summed up Ronny Deila’s Celtic.

At times they were good against Ajax, really good, and played some inventive and attacking football, particularly in the second-half.

But bad decisions, silly, naive mistakes and, to be frank, a lack of quality cost them against the Dutch and that’s five group games, no wins, just two points and that defence have conceded at least two goals in their last seven European matches.

They are out and deserve to be. Celtic should be better than this. The manager has to be better than this because the club cannot allow such failures in Europe to continue.

Bottom of the group is not where the champions of Scotland ought to be. Everyone, from Dermot Desmond down, need to have a rethink because the paying public are being sold short.

On an odd night in Glasgow’s east end, Celtic should have beaten Ajax and it would be difficult to be too critical about this performance on its own. But on the campaign overall, it’s easy to be negative.

Two errors, one from Callum McGregor and another other by Scott Allan – both played well incidentally – lead to the Ajax goals. And on both occasions the men from Amsterdam broke from their own half and found it too easy to get past Celtic’s back line.

This 4-2-3-1 system isn’t working. Too often, Leigh Griffiths was chasing lost causes when his team-mates in the three were in another postcode. Ajax played with three up-front and were always close to one another, which gave the Celtic defence plenty to do.

When Celtic did get forward in numbers, and after the formation was tweaked, they looked a good attacking unit. But too often there was just one or two having a go, and the Ajax defence coped with without too many problems.

It has to change.

Griffiths, who gave his all, will run all day, but why waste such a natural finisher in this manner Surely it would be better to have two men close to him and out wide who can create opportunities for the man.

So what positives? Kieran Tierney again did really well and Celtic might just have a player on their hands. McGregor was good, Allan was bright when he came on, while Stuart Armstrong had his best game for a while.

Poor Gary Mackay-Steven is playing like a man with zero confidence, James Forest was a spectator for long stretches and Dedryk Boyata continues to look like a player who has spent the past few years in the reserves.

Nadir Ciftci and Anthony Stokes remained on the bench during a game their side had to win. That tells you everything about what Deila thinks about them.

Aside from that, the game was really enjoyable.

There was a superb atmosphere way before the match began. Ajax fans are a noisy lot and like a wind-up – there was at least one Rangers banner in the away game – and yet they were silenced almost exactly three minutes into the match.

McGregor took the ball in midfield and made his way with great purpose towards the Ajax goal. He could have passed to Tierney who had made a run to his left, but instead took responsibility and was brave enough to cut in on his right before sending a perfect curling shot into the opposite bottom corner.

He thoroughly enjoyed his moment and was entitled to.

Ajax should have been level not long afterwards when the linesman flagged when Amin Younes laid the ball back for Viktor Fischer who lashed the ball into the net. He was in line and a lucky break for Celtic.

But then young Mr McGregor endured a moment he would rather forget on 22 minutes.

Now you could argue that Mikael Lustig should have taken another option other than to pass the ball to his young-team-mate's feet deep within their own half, but that’s what he did and McGregor’s heavy touch allowed Ajax to attack.

McGregor tried win back only for the ball to go to Lasse Schone who passed to Fischer inside the box. He shot, the ball came back to him and Fischer then headed across goal and there was Arkadiusz Milik who acrobatically forced the ball home from a few yards.

The thing about the goal, apart from the fact it oh so avoidable, was that you sort of knew Ajax would score once they edged into Celtic’s area.

There was a moment four minutes from the break which summed up Celtic’s problems. A long punt from the back found Griffiths who had two giants, Jairo Riedewald and Mike van der Hoorn for company.

The striker did really well to control, stay on his feet, get into the box and then get off a shot on the turn, which went straight to Ajax keeper Jasper Cillessen. Where was the help?

Celtic were much better after the break. Forrest, who grew into the game, made Ajax keeper Cillessen work on 65 minutes when good play between himself and Armstrong ended with the winger’s attempt to aim the ball into the near post, an effort which was read.

Two minutes later and from a break started by Mackay-Steven ended with McGregor’s deflected shot hit the bar. So something was happening out on the pitch.

Scott Allan, for it was he, came on and with his first touch, on 74 minutes, he produced a brilliant pass for Griffiths who was clean through but put his shot not quite through the legs of Cillessen who just made the save.

To be fair to Griffiths, he was on his knees by then, although he should have scored. He apologised on Twitter for a "shocking" performance. That was harsh on himself.

Charlie Mulgrew missed a header at the back post from an Armstrong corner. Then with five minutes to go, Griffiths, who was by now really struggling, failed to score when Armstrong put him through.

And then with minutes to go of a game Celtic had given so much to, Armstrong from a corner opted not to cross but instead passed too Allan at the edge of the box. He had two man on him and no time to take a touch – which he did.

And you just knew that Vaclav Cerny was going to score long before he pulled back his right foot and beat Gordon at this near post.

It has been one of the less memorable European seasons in the history of Celtic.