Given the injury-hit nature of the time he spent at Rangers, former Ibrox midfielder Christian Nerlinger probably doesn’t look back on his Ibrox spell as one of the major highlights of a playing career spent mainly with German giants Bayern Munich and Borussia Dortmund.

Still, it would be quite the turn-up if Nerlinger, now an agent, were to be found cheering on Celtic when they travel across Glasgow to face his former club on Sunday. But according to one of the players on his books, he may well have done the unthinkable - switched allegiances.

As if that wasn’t enough for Rangers fans to stomach, should Celtic winger Nicolas Kuhn play a part in helping his team to victory over their side at the weekend, then their great rivals will have Nerlinger to thank for the part he played in bringing him to Glasgow in January from Rapid Vienna.

READ MORE: McGregor update as Celtic hope for boost for Rangers clash

Kuhn himself is relishing the opportunity to step out at Ibrox with Nerlinger pressing home to him just how special the Old Firm fixture can be, and he is banking on the unwavering support of his agent, despite turning out for the other half of the city from where he once plied his trade.

“I am looking forward to the game against Rangers a lot,” Kuhn said.

“I have heard a lot about it. With my manager [agent, Nerlinger], he played for Rangers. Before I came here, he told me a lot about the match and how important it is to the people. I am looking forward to it.

“There haven’t been any jokes yet [with Nerlinger] – but I think he’s a Celtic fan now! He played a big part in me signing for Celtic. He told me a lot about the club and how great it is.

“Of course, there is pressure. But I played at Bayern and they also want to win every game there.

“I like derbies. At Bayern, we had the derby with 1860 Munich. That was pretty big. I’ve had some good derbies already.

“Of course, it’s massive. I want to play every game. We have a really good team and we are all challenging each other.

“We are all competing and putting pressure on each other for places in the team.”

Kuhn will have done his chances of making Brendan Rodgers’ starting XI on Sunday no harm at all with another eye-catching display in the weekend win over Livingston, with the winger starting to show his quality on a more consistent basis after overcoming his well-documented dental issues.

The weight he lost prior to his arrival in Glasgow has been slowly restored, and so too has the turn of pace that was earmarked as one of his key attributes upon his signing for the club.

“With it being the winter break in Austria, I came here without a pre-season,” he said.

“Ross County was my first game.

“I’m happy that I am back to my normal weight and I have my strength back. I’m maybe not 100 percent just yet, but I’m definitely getting better and better.

“I thought we played a great game [against Livingston]. Defensively we were strong because Livingston had no chances.

“In the second half, we were happy to get the first goal. Then we found more space and made it 3-0. The attacking side of our game has been good recently.

“For me personally, it took some time for me to get used to the new system. But now it feels like it’s getting better and better with every game.”

One of the things that helped Celtic feel at home in Livingston was the fact that three quarters of the stadium had been turned over to their supporters, something Kuhn was taken aback to witness.

READ MORE: Celtic ready for Rangers as Reo Hatate leads returning cast

It will be one extreme to the other when they walk out at Ibrox though, with the new agreement over away allocations that was brokered last week not coming into effect until the start of next season.

That means there will be no Celtic fans in attendance outside of the director’s box and the dugout, but Kuhn is confident they can block out the noise from the home supporters, just as his teammates did when winning 1-0 at the stadium back in September.

“It was unbelievable [at Livingston],” he said.

“It felt like a home game. The fans were great.

“For next week, we need to focus on ourselves.”

The Old Firm game will in effect be the starter’s pistol for the final run-in towards the league title. If there is a victor, then they will surely be  strong favourites to go on and lift the trophy.

Far from being daunted by the importance of the game though, Kuhn says the Celtic players are relishing the challenge of what lies ahead over the next week, and the weeks to come.

“We have to be excited,” he said.

“We want to collect the points and we know we need to play well.

“We’re in a good place now and you can see the attack has been good in the last few games. The defence is also strong, so we feel happy about what is coming.”