Ronny Deila can have few illusions about the true test that awaits him as manager of Celtic in the weeks ahead.

After a strong, disciplined performance by his players against Qarabag over 180 minutes, Celtic are through to the Champions League play-off round.

Against Qarabag, Deila showed further impressive evidence of a football manager in charge of his own destiny, with players who have an unflinching faith in their coach. It looks the perfect domestic.

But here comes the litmus test.

Deila cannot allow two football seasons to pass without his Celtic team taking part in the Champions League group stage. It would be a failure only he would be held accountable for.

After last season’s atrocious botch against Maribor – when a win or a 0-0 at home against the modest Slovenians was messed up by Celtic – these looming play-off games on August 18/19 and 25/26 have a weighty significance.

Last season Deila was only three months into the Celtic job when Maribor came to Glasgow, but even that seemed a lame excuse for slumping to a team that went on to finish bottom of its Champions League group with three points from six matches.

In his heart Deila knows the truth of it. Taking part in the Champions League is the great stimulus for the Celtic support, many of whom view the chore of the domestic league with a grim forbearance.

If there is to be no Champions League at Celtic Park this season, many Celtic fans will have to be roused from their hearths to head out to witness the epic battles against Partick Thistle, Kilmarnock, Ross County and the like.

The play-off draw this Friday also looks pretty kind to Deila and Celtic. Seeded in the champions route of the draw, Celtic will face one of Maccabi Tel Aviv, Partizan Belgrade, Malmo, Skenderbeu Korce or Astana.

After last season’s Maribor flop, no-one will treat lightly any of these five opponents. But Celtic, due to the qualifying road-map of the Champions League, are far better facing these teams than Manchester United, Monaco, Lazio or CSKA Moscow, all of whom are also trying to negotiate the play-off round.

In short Deila has another great chance – and a generous one – to lead Celtic in among the elite. He surely has it within him.

Still just 39, this Norwegian coach grows on you with every passing month. The full bloom of his coaching career is surely still ahead of him, and the truth is, Celtic, like Stromsgodset, may just represent the early foothills of Deila’s career.

It is interesting that in Norway he is still viewed as a coach of potential, a man yet to fully prove himself. Deila is still very much “in the making” which is why it was a risk – an imaginative one – for Celtic to appoint him in the first place.

“It was a surprise to the people of Norway when he became the Celtic coach,” said Anders Konradsen, a Norwegian international now at Rennes, who played for Deila at Stromsgodset. “It’s hard for me to say whether Ronny is a Champions League coach right now. But I feel he definitely has the possibility to become one.”

As well as his coaching ability, Deila has certainly grown in character and fortitude over the past 12 months. It can only stand him in good stead.

This time last year a storm was brewing for him. His team would lose to Caley Thistle, draw at home to Motherwell and lose to Hamilton Accies, let alone the Maribor debacle.

At the time more than one prominent Celtic fan said: “Okay, it is time to cut our losses and end this Ronny Deila experiment…” The writing appeared to be on the wall for the doomed coach.

But Deila came through all that, won round the Celtic support, and by the early months of 2015 was being feted wherever he took his team. He has come through the fire at Celtic, seemingly undamaged.

Taking Celtic into the Champions League in the next few weeks is by no means a given. But it is an expectation. Deila needs to pass a test which he disastrously failed last year.

Twelve months on he looks a more confident, assured and assertive manager.