STEPHEN O’Donnell must have thought his path with Nicklas Bendnter would never cross again.

When you leave Arsenal for Falkirk, as O’Donnell did in 2005, before spending the rest of your career in Ireland, the chances of bumping into one of the most talked-about players in Europe are slim.

However, O’Donnell did just that, last Wednesday, in the Leerkendal Stadium in Trondheim. Bendtner was on the opposite side of the Champions League divide to O’Donnell’s Dundalk, as Rosenborg snatched away the prize of a third-round qualifying encounter with Celtic.

The Irish midfielder and once-great Dane swapped memories of their time in Arsenal’s youth system, and O’Donnell is convinced that Bendtner still has something to offer, even if going to the far north of Norway to find a club was never on the horizon.

O’Donnell believes that a huge stage like Celtic Park will bring out the best in Bendtner tomorrow, and that the 29-year-old Rosenborg striker will be a threat to Brendan Rodgers’ side.

“Nicklas is still a big, big boy and a huge physical presence,” said O’Donnell of the 6ft 5in Dane. “He’s not changed much as a player. He is still a handful for defenders in the air and a good first touch on the ground.

“Nicklas will be a threat to Celtic, although I felt we handled him quite well last week because Rosenborg didn’t give good service in terms of crosses.

“He used to thrive playing on the biggest stages with Arsenal and Denmark and I’m sure that playing at a sellout Celtic Park in a Champions League tie will bring out the best in him.

When O’Donnell said goodbye to Arsene Wenger in 2005, to move to Scotland, the Arsenal manager was handing Bendtner a first-team debut at 17 and a year later, the teenage striker received the first of his 74 Denmark caps, aged 18.

The contrast was greater in 2010, when Bendtner played in the World Cup finals, while O’Donnell swapped Cork City for Galway United, one of the midfielder’s five clubs in his native country, with manager Stephen Kenny also taking O’Donnell to Shamrock Rovers and Dundalk where the pair have enjoyed European campaigns.

Bendtner, though, is neither loved by club or country. He was kicked out by Arsenal and Denmark and a lifestyle that saw him better known for car crashes than goals, means he’s now at Rosenborg.

Juventus would not touch Bendtner after he was arrested for drink-driving while on loan during 2012-13 and the Danish FA banned the striker for six months from the national team for that offence.

In August 2014, Bendtner signed a three-year deal with VfL Wolfsburg but the Bundesliga club ran out of patience and terminated his deal after two seasons. According to sporting director, Klaus Allofs, the Dane “was a menace to the club” because of so many lost nights and missed training sessions. Bendtner then had six months at Nottingham Forest before joining Rosenborg last March.

“He’s had a few clubs where things have not worked out for him,” said O’Donnell. “I’m sure Nicklas thought he’d be at Arsenal forever.

“I was two years above him at Arsenal,” said Stephen, now 31. “He was so highly-rated an Arsenal brought him in at 16 from Denmark. I came over from Ireland at the same age, so I looked out for him a bit because you know how home-sickness can get to players.

“Nicklas and I spoke during the game in Trondheim and then after it. He says he is enjoying himself. Rosenborg is still a big club, in European terms, and he’s only 29, so Nicklas still has time to do well.

“Rosenborg know that if they beat Celtic, that would guarantee European football even if they didn’t get through the play-off, because they will have the Europa League to fall back on.

“That’s what we did with Dundalk last season. We were narrowly knocked out by Legia Warsaw in the play-off but had a great experience in the Europa League group stage.

“We were very close to beating Rosenborg. We were the better side in the first match in Ireland when we drew 1-1 and threw a lead away in Norway when leading 1-0, to go into extra-time. We hit the bar with a few minutes to go when they lead 2-1 which would have taken us through.

“That’s how close we came to having a tie with Celtic. Such small margins. We were dreaming of sellout game with Celtic at the Aviva Stadium in Dublin, which is what we did with Legia last season.

“It will be interesting to see how Rosenborg do against Celtic . They are a decent side but don’t have a lot of pace, especially at the back, which is maybe something Celtic can exploit.”

It is a huge irony for O’Donnell that he felt the need to watch out for the shy young Bendtner at Arsenal, because the Danish striker became so over-confident in London that his arrogance earned the nickname ‘Lord Bendtner.’

The name was partly inspired by Bendtner dating Baroness Caroline luel-Brockdorff in 2009 – a friend of the Danish royal family. Caroline gave Bendtner a son and then the pair separated.

But the ‘Lord Bendtner’ name stuck in Denmark, so much that he was given some land in the Scottish highlands in 2015 to heighten the ‘claim’.

It was part of a PR stunt from Danish magazine SE Og HOR, which purchased one square foot of land in Glencoe Wood – part of a nature reserve.

“We have seen it, and Nicklas thinks it’s a fun gimmick”, said Elisa Lykke, Bendtner’s agent. “We are pleased that it supports a nature conservation area.”