The step back has allowed Kristoffer Ajer to take a massive step forward.

Going from midfield to central defence has been a logical progression for the player who stands at 6 foot 5 inches and the teenager has now set his sights on continuing his education with further exposure to the first-team.

Celtic will jet out to Dubai on Saturday for a mini pre-season as they look to the latter half of the campaign but Ajer is desperate to continue where he left off.

Read more: Celtic captain Scott Brown insists Hoops won't be taking it easy in Dubai

The 19-year-old Norwegian had contemplated a loan move in the current window, a situation that has been revised since his elevation into the senior team.

With Erik Sviatchenko expected to move on this month as he looks for regular football and Jozo Simunovic also re-igniting the interest of Sean Dyche at Burnley, it is unlikely that Ajer would be allowed to go anywhere.

And if recent weeks are to be seen as a barometer of what is to come, it may be that Ajer’s conversion from midfielder to centre-half is continued with the experience of Marvin Compper beside him.

“There is so much competition here but I feel like a completely different footballer now from when I first arrived at the club,” said Ajer.

“I have worked hard physically in the gym to try to build myself up and be a bit more powerful but I have also worked very hard on the training ground. I feel as though I have learned so much, even when I have not been playing.”

Moving further back from the central pastures has been a learning curve for the teenager.

There remains a rawness about the player in the role and for all that he impresses when carrying the ball out from the back, it is inevitable that if he is to have a future in defence that there will be a fair amount to get his head around.

“I am pleased with it,” he said. “It has been something that I spoke to the gaffer about in the summer and I always felt that there would be a point where I would move to defence in my career.

Read more: Celtic captain Scott Brown insists Hoops won't be taking it easy in Dubai

“I think playing in midfield has given me a good start to my career but this is the next step for me and I have been working really hard to learn the role.

“Kolo Toure and all the other senior players have been excellent with me. I have learned so much by watching them and listening to their advice because they have all been there and done it before.”

It is a mark of the faith that Brendan Rodgers has in the player that he was willing to stick with him for the game against Rangers.

As expected, Ajer described it as the biggest game of his career to date but was unruffled by the build-up to the encounter.

“I didn’t know I was playing until the manager read out the team the day before – that is the way it always is, so there was nothing unusual,” he said.

“I wasn’t sure whether I would start or not so I was really pleased when I knew that I was going to play. It is a huge fixture and I really enjoyed it.

“I had to be physical and I had to be strong but it was a great game for me to play in and definitely the biggest game I have played in my career.

“The manager told me before the game to play my own game and relax and I felt as though I was able to do that. It has been a great experience for me to be involved in the games I have been in December.

“But I know that if I want to keep my place that I have to keep working hard and keep trying to impress the manager. It is not easy when you come to a club this size.

Read more: Celtic captain Scott Brown insists Hoops won't be taking it easy in Dubai

“It has taken me a while to settle in but I feel relaxed and I do feel that I have improved hugely since I got here. Hopefully the next step for me is to get some more games in the first-team but I understand that there are a lot of players who want to do the same.”

When Ajer first arrived at Celtic he hoped to combine his playing career while also continuing his studies.

The teenager was hoping to embark on a medical career in Norway when he was signed by Celtic and was optimistic of transferring to Glasgow University in order to study part-time.

However, while he has continued with general studies through distance learning since he has been at Celtic, he has decided that his full focus now will be on football with any further studying coming once he hangs up his boots.

“I have one more subject to finish and then I think that will be me for a little while,” he said. “It is just a general subject. I think right now I have to fully focus on my football. It is a short career and I want to make the most of it.

“Once I stop playing then it is definitely something that I would think about going back to.”