Ronny Deila has warned Celtic that while Rosenborg are not the Champions League side they once were, they would be foolish to underestimate the Norwegian champions on home soil.

Celtic host Rosenborg next week as they look to establish a strong foundation before the return leg a week later in Trondheim.

And Deila believes that whatever happens at Celtic Park will be pivotal in deciding the fate of the tie.

Read more: Former Hoops boss Ronny Deila will turn double agent as Celtic and Rosenborg go head-to-headGlasgow Times: Former Celtic manager Ronny Deila believes the first leg in Glasgow will be key to the club's Champions League tie against Rosenborg

“This is a Rosenborg team who are not as strong as they were in the late 90s and early millennium, a team that regularly punched above their weight in the Champions League,” said Deila. “To be honest, they are probably not as strong as they were even a year or two ago but what they do have is the same philosophy that has served them well over the last 30 years or so.

“They have a strong collective, they play as a unit, they are a disciplined team and they are very good on home soil. They will have 23,000 supporters inside the stadium and they create a good atmosphere. They will get good support.

“Their midfield is probably where they are strongest. Niklas Bendtner would be their most well known player and in a game like this you would expect that he would be keen to show the skills that he has. He gives them a bit of energy and he also has a lot of experience which is so useful at these times.”

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And if anyone knows the tension that comes with trying to get Celtic into the group stages of the Champions League, it is Deila.

The former Celtic manager could not lead the club into the elite playground after two attempts and he fully appreciates the pressures that come at this time of year. As such, he believes that it is vital that Brendan Rodgers’ side establish a commanding lead before jetting to Norway and a second leg that could well be a little jittery.

The draw brings back uncomfortable memories for Deila of Celtic’s aggregate defeat to Malmo two years ago when a 3-2 home win was rendered insufficient with a 2-0 defeat in the second leg Sweden.

At 2-0 up at Celtic Park and just before the break, Stefan Johansen missed a glorious chance to put the game out of sight, a miss that would wound Celtic when Deila’s compatriot, Jo Inge Berget sprung a 94th minute goal that irrevocably altered the balance of the tie.

Little wonder, then, that Deila stresses the “small details” that proved ruinous to his European aspirations at Celtic.

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“I know more than anyone just how tense these games are,” said the affable Norwegian. “It is small details that are the difference between success and failure. Rosenborg hold an advantage over Celtic in that they have already played 15 league games this season so they are sharp, they are at their peak in terms of fitness and they will look to use that.

“For me, it is very similar to the game we played against Malmo a few years ago and I think the first leg in Glasgow will be so important to the tie.

“Celtic on paper are the stronger team but in these games you need to take your chances, you need to be clever when you are at home. If they score a few goals and don’t conceded then they will have the upperhand but I would stress that you cannot write off Rosenborg on their own turf. They are capable of hurting their opponents but I would imagine that Brendan Rodgers will not take anything for granted.”

Despite the fine lines that undone Deila’s Celtic, he is not bitter at how else it might have gone for him.

“I don’t look back and think that I had wished it had turned out differently and that I had got Celtic into the group stages,” he said. “I can feel positive that I give Celtic my best and we came so close but we just were not good enough. But I had a very happy experience. I was there for 26 European games which is a lot and I learned so much from that time. It was such a great chance for me but we had a young squad who have learned and improved since then. That will be so important now as they look to get back into the Champions League.”

Read more: Former Hoops boss Ronny Deila will turn double agent as Celtic and Rosenborg go head-to-head

Scott Brown was statistically one of Celtic’s finest performers in the Champions League group stages last season with his ball retention and delivery of passes.

His performances last term, vastly improved from Deila’s final season in charge, were pivotal to Celtic and the way they played and the Norwegian has stressed the importance of that experience as the club look to get themselves back into the elite playground of the group stages.

“In games like these when it is tense, there is so much pressure riding on them and so much at stake then you need to have a leader,” he said. “I think Scott Brown improved so much again last season and in the European games I saw he was better on the ball, he was sharper, quicker and he has always been a leader.

“You need to have a leader in a situation like that. You need someone who can go and take charge and be comfortable under pressure. I know that he will be given a testimonial by the club which is great news for him because he has been such an important part of the club and has played such a big role over the last decade.

“You need experience and I think that in games like these when it is so tight then the fact that Celtic were in the Champions League group stages last season will help them enormously. They have that now and for all the players who hadn’t experienced that before, they will have taken so much from it. “