Donovan started for Celtic in place of the injured Alistair Johnston and stood out at right-back.

Strong in tackles and more than adept on the ball, he displayed maturity beyond his 19 years.

Speaking in the mixed zone after the match, Donovan’s delight was apparent.

“I try and give my best for the badge every game I go into,” he said. “Every time I put on the Celtic jersey, I always give 110 per cent.

“Hearing the fans before the game with that Champions League anthem, it was so special.

“Coming here on special nights like this, it’s what you dream of, isn’t it?

“This is what I want to play in, I want to play in the highest competition. This is the biggest one, so hearing that, it gave you an extra 10 per cent boost.”

Colby Donovan celebrates with Camilo Duran after Celtic’s third goal against LASK. (Image: Stuart Wallace / Shutterstock)

Donovan’s reality is every Celtic fan’s dream. He made his senior debut 12 months ago and has remained a regular first-team fixture since.

Such was the quality of Donovan’s performance on Wednesday, his development in the past year is something to behold.

Manager Martin O’Neill sang Donovan’s praises after LASK, lauding his ‘boundless enthusiasm’ as a ‘local lad’.

“I used to sit in these stands and listen to the Champions League anthem and watch the boys. For me to actually do it, words actually can’t describe it,” Donovan added, reflecting on the surreal nature of his rapid rise.

“I look up after the games and I see my family. But sometimes in the games, most of my pals are in the Bhoys and all that. So I look up and I always see them. I’m loving it man, I’m loving it.”

Donovan was among those friends at Fir Park in May when Celtic took a giant step towards the title with a frenetic 3-2 victory over Motherwell, sealed by Kelechi Iheanacho’s 97th-minute penalty.

Not in the squad that night, he travelled to Lanarkshire as a fan. On social media, clips later emerged of Donovan celebrating on the turf with his fellow supporters after Iheanacho scored, eagerly embracing former teammate Arne Engels.

That celebration wasn’t unusual for a youngster who’s always enthusiastic when his team scores. When Donovan was in the academy, he regularly jumped up pitchside at Celtic Park as a ball boy.

“I ball boyed a few times, to be fair,” he recalled. “I remember the one game, it was St Mirren at home. Celtic scored and I was up running like a daft man!

“I was on the park at Motherwell away as well!”

Naturally, given his background as one of Celtic’s own, Donovan would be forgiven for feeling nerves every time he takes to the field.

Even on Wednesday, though, as he lined up alongside his teammates against LASK, he was more keen than trepidatious.

“I hardly get nervous for games, I’ve never been nervous for a game to be honest,” Donovan said. “Coming out, you just need to play your own game, you’ve done it all your years.

“It’s nothing strange, it’s the same pitch, it’s the same ball. You just need to play your football at the end of the day.

“Coming out of the tunnel today, it was more just that excitement and wanting to go out there and play and show the fans what we can do.”

Alongside the Celtic support, Donovan showed new Scotland head coach Sebastien Pocognoli what he can do against LASK.

The Belgian watched on alongside SFA chiefs Ian Maxwell and Craig Mulholland at Celtic Park.

Appointed with the view of integrating the country’s top youngsters into the senior national team setup, Pocognoli would have been impressed with Donovan’s display.

The full-back has already represented Scotland at various youth levels, and while he remains focused on life at Celtic, further international recognition might not be a million miles away.

“I just want to do the job for the club, going into games,” Donovan said, when asked about Pocognoli’s presence. “I kind of don’t think about that.

“After a game, you see it on your phone on social media and all that. Obviously the new Scotland manager has come in.

“You just need to give 110 per cent performance for your club and give him a thought that maybe this boy can play. For him, hopefully, I’ve played a good part in the game tonight.”

Donovan has proved an able deputy to first-choice Celtic right-back Johnston at the start of the new season. The Canadian remains sidelined with a hamstring injury after an eventful summer in which he stood out for his country at the World Cup.

“You learn from Ali every day,” Donovan said. “You see him in the World Cup – he’s a top, top player. Learning from him, seeing how he plays – you want to put stuff from his game into your own.

“There’s no other person you want in front of you.”

In replacing Johnston for a game of such significance, did Donovan feel the pressure?

“I don’t really bother,” he said. “Somebody’s got to fill his boots and put a performance in that people will be proud of. Hopefully I’ve done that for the fans tonight.”

Donovan certainly did. Now, with Celtic holding an assertive 3-0 advantage over LASK, the second leg, and a potential berth in the Champions League proper, awaits.