If nothing else, Kristoffer Ajer has certainly proved that he is adaptable since he arrived in Glasgow to begin pre-season training with Celtic as an 18-year-old in the summer of 2016.
The changes have subsequently come thick and fast and he has coped with all of them. He was persuaded to join the Scottish champions from IK Start by his fellow Norwegian, Ronny Deila, but by the time he reported for duty, Deila had departed, replaced by Brendan Rodgers.
Ajer had been signed as a midfielder (at 6ft 5in he had also occasionally been deployed as a target man by Start) but Rodgers, who likes his defenders to be able to pass the ball, immediately decided to reinvent the teenager as a centre-back.
The height and his distribution provided him with a head start in that regard but he has had to learn his new position on the job. He made his debut for Celtic in the Champions League qualifying round victory over Lincoln Red Imps but did not feature for the first team again that season, spending the second half of it on loan to Kilmarnock, with the proviso that he played in the heart of their defence.
Thrown into the deep end of a relegation battle with the Ayrshire club, Ajer admits the 17 appearances he made under Lee Clark and Lee McCulloch helped to precipitate his progress.
Now he faces yet another role as he prepares for one of the defining fixtures of the Premiership campaign, against Rangers at Ibrox on Sunday. When Celtic won 2-0 there in September, Ajer was not even on the bench and sat with the travelling support in the stadium.
On Sunday, however, whether Rodgers decides to go with three or four at the back, Ajer will be in his starting line-up, having established himself as a fixture since exploiting the absence of first Jozo Simunovic and then Dedryck Boyata through injury.
Victory for Celtic will put an end to talk of a title challenge by the home side but Ajer is taking nothing for granted.
“It will be a tough match at Ibrox and it is a big game for both clubs,” he said. “I travelled there the last time but I wasn’t in the squad. I sat in with the Celtic fans and it was a good experience.
“We won 2-0, it was a good result – but I wasn’t singing. I am still trying to learn the songs!”
Ajer believes he proved his credentials when he played in the 0-0 draw between the derby rivals at Parkhead on 30 December and he will use what he learned that day to deal with this weekend’s encounter.
“Starting the last game against Rangers was a big moment for me,” he said. “We kept a clean sheet and did pretty well defensively.
“Craig Gordon had a fantastic game; he made one or two big saves for us. After that, it gave me a chance to kick on.
“I know that when you play centre-half for Celtic, you are expected to deliver every single time. I need to be 100 per cent ready for everything.
“You need to have the right mentality to play in those games. You need to be focused. You need to concentrate on the pitch and not [pay attention to] everything else around it.”
Rangers are the top tier’s leading goalscorers and Ajer is looking forward to the challenge of stopping their top marksman, Alfredo Morelos, pictured, who has yet to find the net against Celtic.
“Morelos is a very good striker; he runs a lot and fights, so it was a tough test against him,” he said. “But I have been impressed with all the strikers in this league.”
Should Rangers prevail on Sunday, Celtic’s lead at the top of the table will be slashed to only three points (albeit they have played one game fewer than their opponents). Ajer, though, turns a deaf ear to the conjecture.
“After training, I try to stay away from all that happens in Glasgow between the clubs,” he said. “It’s important you don’t think about anything else apart from the games; it takes away energy if you do that.”