CELTIC boarded the plane to Malmo this morning having ensured the domestic frontier is left in good order.

The challenge now lies in ensuring they are still flying high come tomorrow night.

Ronny Deila watched with some satisfaction as what was essentially a Celtic second string saw off Dundee United with a comfortable 3-1 win – a victory which came with the added bonus that both Kris Commons and Charlie Mulgrew returned from injury in time for tomorrow night’s critical game.

Just like the first leg against Malmo, Celtic emerged from the Tannadice tunnel on Saturday afternoon with their immediate sights set on the jugular.

If that aggressive display of attacking invention with Leigh Griffiths at its forefront gave Deila encouragement that a victory is well within Celtic’s grasp tomorrow evening in the Swedbank Stadion, there were also brief lapses in concentration that may cause some anxiety.

Efe Ambrose had a decent game against United but his tackle on Scott Fraser gave Chris Erskine a goal from the spot.

It meant that a half which Celtic had dominated entirely concluded with United still in it when really Celtic ought to have been out of sight. The worry is that it is becoming something of a pattern.

Yet, if there are any doubts on Deila’s part, they will remain private.

“I am confident,” said the Hoops boss as he looked ahead to tomorrow’s game. “We have not lost a game in near on four months so why should we lose now?

“Of course there are nerves ahead of the game but I am looking forward to it. You should look forward to a game like this.

“We have prepared right. Our heads are right. Our bodies are right. We have to go out and play. If we concentrate, focus, work hard then why should we not win the game?

“We showed against Dundee United and we showed in the first half against Malmo that we are hard to deal with when we are attacking teams.

“But we want 90 minutes of that now. That is the challenge but I believe in my players and I believe that we can do it.”

Certainly, while Celtic were irrefutably guilty of sloppiness in the latter stages of the opening leg against the Swedes when they allowed Jo Inge Berget to snatch a 95th minute winner and claim a goal that altered the nature of the tie, Deila’s was also keen to highlight that there was much about the game that Celtic got right.

In that respect, that late goal can be confined to a momentary blip should Celtic prevail in Malmo. The danger, of course, is that its unnerving impact defines the tie – and not in Celtic’s favour.

Such is the precarious balance of the contest, and Deila has acknowledged that the psychological aspect of tomorrow’s game will be vital.

“It is a tough mind game now to get things right,” he said. “The mental aspect to our approach is very important. But we haven’t lost a game since the semi-final of the Scottish Cup.

“That has given us a lot of confidence and you have to remember also that we had a victory on Wednesday night – we did actually win the game.

“Malmo still have to come out and beat us if they want to go through.

“We need to be clever. We have to be careful but it is important that we create chances and cause them problems. I believe that if we are strong defensively that leads to us being successfully offensive.”

For Deila himself there is also the pressure of accepting that the perception of just how successful his 14-month tenure at Celtic has been will be judged on the next 90 minutes.

Successfully guiding Celtic through three qualifiers and into the group stages of the Champions League will ensure he follows a pattern set by Martin O’Neill, Gordon Strachan and Neil Lennon who all achieved that feat in their second season in charge of the Parkhead side.

And it would polish his reputation both in Glasgow and further afield in a way that domestic success cannot. He said: “It is a dream of mine to manage in the Champions League.

“It is the goal of everyone associated with the club. We have a chance now, a big chance, and we have to take it.”

There are options as to how Deila approaches the game against Malmo, even if Mikael Lustig, as expected, does not make it. Mulgrew will be drafted back into the team while Griffiths’ form – the striker netted his seventh goal of the season against Dundee United – suggests that it would be madness to overlook him in favour of Nadir Ciftci.

Saidy Janko also performed reasonably well in the right-back berth against the Tannadice side.

And Scott Allan’s debut was almost marked with a goal as gallus as his chat – his audacious chip when he was on the park for only a minute caused a momentary flutter for United keeper Luis Zwick. Malmo have Markus Rosenberg to return as well as midfielder Enoch Adu and the Swedes have shown in the previous round that they can make life uncomfortable for their visitors.

Celtic fans will not want reminding that the Swedes overturned a 2-0 deficit in front of their own boisterous support against Red Bull Salzburg to progress to this stage.

“I have followed the career of Markus since he was just starting out,” said Deila.

“I know that he is a good player but we have players who are capable of stopping him. That will be important. We know the importance of concentrating and keeping our focus and I believe we have players who can do this. We have put ourselves in a good position.”

Closer to home, the fact that Deila could make nine changes to the team which beat Malmo and come away from Tannadice with a win has underlined the strength in his squad.

This time last year 10 changes to his team at Inverness did not result in the same outcome and the Hoops boss drew many positives from the victory over Jackie McNamara’s side.

“It says positive things about us that we can change it so much and still play well,” he said. “We have players that can do it and we need that when we are going to play big games – and so many games.

“We hope that we will be playing Champions League football and league football so we need this squad. You can see the belief that the players have in one another.

“Eoghan O’Connell played well. He is a talented lad. He showed calmness and good technique and it was a good 90 minutes for him to get.”