LIKE most football-obsessed 18-year-old boys, Kieran Tierney spends a significant amount of his free time playing FIFA 2016 on his PlayStation with his mates. Unlike the vast majority of his contemporaries, however, the Celtic left back can sign himself on it.

“What I do in my life is no different,” said the PFA Scotland Young Player of the Year nominee when asked what has changed for him since he has broken into the first team at Parkhead.

“If I am walking about I do get recognised more. But I just do my usual stuff, like playing my Play Station. That has probably been the biggest change for me - going from Xbox to PlayStation.

“I’ve seen myself on the PlayStation, but I’m not too good on there. My pals keep slagging me off because I have the worst rating in the team. I don’t even sign myself, it’s a waste of money.

“I’m not even sure it’s a great likeness apart from the hair. It’s weird. When you are a wee guy you call your character Kieran Tierney - now it really is Kieran Tierney.”

The fact he now has his very own digital doppelganger sums up the dramatic rise to prominence that Tierney, the childhood Celtic fan from the Isle of Man, has undergone in the 2015/16 campaign succinctly.

He had made just two appearances and one start for the first team before it got underway. Since establishing himself as a regular starter, he has been one of the Scottish champions’ most consistent performers and become a firm fans’ favourite.

“I never thought in a million years I would be in this position,” he said. “I’m really grateful because the season has gone better than I could have hoped. I’ve played more games than expected and it’s great to be nominated for this award.”

Tierney’s third start for Celtic must have felt something like a scene out of a computer game for him. He was selected to face Fenerbahce - Raul Meireles, Nani, Robin van Persie et al -in a Europa League group game in front of a crowd of 41,330 at Parkhead in October.

The slight defender wasn’t overawed by facing the expensively-assembled Turkish club and, as has so often been the case in the months since, was actually one of his side’s better players as the Scottish champions earned a 2-2 draw.

“I’ve learned a lot,” he said. “It’s been a big jump from the under 20s to first team football. You need to adapt to the physical side pretty quickly. My fourth or fifth game in was against Fenerbahce. I remember thinking, ‘wow, this is hard’. It was big, but those are the games you want to be involved in.

“You can’t allow yourselves to get too nervous. I knew beforehand I was up against players like Van Persie and Nani. People told me on social media that at that time Nani had won more Premier League trophies than I had made league appearances. But you can’t think about that stuff.

“I think the manager and the fans thought I’d done okay in that match so it would be okay to play me in the league games. It showed I could handle it. The fans have been amazing with me. They give me plenty of support and confidence. You can hear it.”

Tierney has been one of Deila’s great successes during his turbulent two year tenure in Glasgow. He will mourn the departure of the Norwegian coach who has put such faith in him in the summer even if a fair few of his team mates won't.

“The manager has been great with me,” he said. “I can’t thank him enough for everything he has said. It gives you a lot of confidence. We want to give him the perfect send off by winning the title. The last four games are very important for us and we want to wrap it up as soon as we can.

“When I came up from the under 20s I was sitting on the bench every week and there wasn’t much chance to show what I could do. But he watched me closely in games and in training. He’s been great for me. I will forever be thankful because if it wasn’t for him I wouldn’t be where I am.”

Tierney, who became the youngest player to be capped by Scotland in 53 years when he started in the friendly international against Denmark at Hampden last month, appreciates he will have to prove himself all over again when Deila’s successor as Celtic manager is appointed during the summer.

“I will definitely have to impress the new manager,” he said. “It’s the same for the older guys as well. The new manager will come in and we all have to impress him. It won’t matter what we have done in the last season - it’s all about the new season.”