Ronny Deila, the former Celtic manager, has told the Parkhead side that he is willing to provide the lowdown on Rosenborg, whom Brendan Rodgers’ side face in the UEFA third-round qualifiers next week. 

However, while the Norwegian is happy to give the ins and outs of the premier team in his homeland, he has warned that he fully anticipates being asked to turn double agent and give his fellow countrymen inside information on what they can expect from Celtic.

“ I would gladly given the club information on Rosenborg,” said Deila.

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The Herald: 'It's going to be tough, but I do think they will do it,' says Ronny Deila

“Although, it works both ways – I am sure that Rosenborg might ask me for some information on Celtic too so I might be working two tickets! I am happy to help both of them and this is a game that won’t be won on what I tell either club, it will be decided by who plays well over the course of two games.”

The 42-year-old had a difficult time latterly at Celtic but he retains an affection for the club. And while he has acknowledged that he enjoyed watching Rodgers’ side in the group stages of the Champions League last season, he has conceded that he has mixed feelings when it comes to seeing the Parkhead side prevail against Rosenborg.

Currently in charge of Valerenga in his homeland, Deila would love to see a Norwegian representative at Europe’s top table, leading to mixed affections when the game comes around. 

“It is a very interesting tie, especially for me,” he said. “It is a hard question too, who I would support. I am a proud Norwegian and I want to see Norwegian football represented at the highest possible level and it would be fantastic for the profile of our game to have a club in the Champions League. However, I am also a Celtic fan too and I would love to see them get back into the Champions League. 

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“For the club as a whole, for the support and all the players, I loved seeing them in the competition last season so I am pulled two ways. I know what it would mean for Norwegian football to have one of our teams do well in Europe, so the only thing I can say is that if anyone is to put them out then I hope it is Celtic, but it is a hard one for me.”

Rodgers has described the second leg of Celtic’s game against Hapoel Be’er Sheeva last year, the game that unlocked the key to the group stages, as the longest 45 minutes of his life while his assistant, Chris Davies, revealed that he had a migraine on the bench throughout the tie given the pressure associated with the 90 minutes.

If anyone can appreciate the precarious nature of the qualifying games it is Deila who twice failed to get Celtic into the promised land. When the draw was made, a torturous night in Malmo came to mind for the former Parkhead manager, prompting his own theory that what happens next Wednesday night in Glasgow will be key to how the tie turns out.

At 2-0 up at Celtic Park and just before the break against Malmo, 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 prove so vital on those occasions. 

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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 concede then they will have the upper hand, 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.”

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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 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. “