As Ange Postecoglou assessed the candidates to replace Scott Brown as Parkhead captain this summer, there really was only one man for the job. At 28, McGregor's moment had arrived.

On Saturday, he ticked another box in terms of his career and he would wear the armband of his country as Steve Clarke's side saw it out against Moldova at Hampden.

McGregor has always been an assured, composed figure in the middle of the park and once the final whistle has blown and his status for club and country has been well earned.

He is a man and a player who is an example to follow. He is a captain who looks to lead in the right way.

"I feel comfortable in that role," McGregor said. "It's a change but I feel good and I feel like I have played well.

"The performances have been good and the results have been decent, so you gain confidence from that.

"When things are going well and you feel that responsibility, it's good.

"You are always learning but it's something I am settling into.

"It changes you in the sense that you become more responsible for your team-mates.

"You try to help them a little bit more and you always have to set the example for others to follow.

"The good thing about this Scotland squad is that we have a few captains and leaders.

"I always think the best teams are built on having three, four, five guys in the team who can take responsibility at any given time.

"You can't just put that on one person in this day and age, with the way the game is played.

"That's a big ask so all the other guys need to chip in and help Andy Robertson as well. That is going to be vital moving forward."

McGregor has been a hugely influential presence in the green of Celtic and blue of Scotland for some time now and his role at Parkhead and Hampden cannot be understated.

It was, of course, the midfielder that scored Scotland's only goal during the European Championships as Clarke's side dared to dream and ultimately fell short in Group D.

The experience has undoubtedly benefitted the national squad and whetted the appetite for future success now that Qatar is in sight.

McGregor only needs to think back and look forward to realise that ambition is easier said than done, though, ahead of a potentially defining 90 minutes against Austria.

"You get older and you realise that tournaments are hard to get to, hard to play in," McGregor said.

"When you are younger you say, ‘there’s the next one and then the next one.’ I’ve heard that story so many times.

"Even when I was younger I heard it from the experienced guys, who were the same.

"You keep saying, ‘next one’ and then suddenly you are running out of time.

"That knowledge makes you appreciate a bit more the opportunity that you have.

"Playing in the Euros in the summer gave everyone a taste of it and we are desperate to get there again and hopefully get to a World Cup as well.

"No, I don’t think [I can remember the last time Scotland played in a World Cup.] I was really young and if I’m honest I don’t really remember it.

"What the long gap shows you is just how difficult it is to get there. The game is evolving so much and you need to show real quality to get there.

"The fact we managed to do it in the summer will give everyone confidence.

"And it makes you appreciate playing at that level and makes you desperate to experience more."

The next stop on that journey is Vienna. If Scotland lose to Austria this evening, it would be the end of the road in terms of their World Cup bid.

The win over Moldova at the weekend took Clarke's side to eight points from their five fixtures in Group F and another victory would be a timely shot in the arm for Scotland.

It is make or break. Indeed, it is Scotland's most significant qualifier since that historic night in Belgrade last November.

McGregor said: "I suppose it is similar to that Serbia game.

"Firstly, we want to win the game and three points would be massive for us.

"But on the other hand, if we get a point then it's not the worst result.

"With four games to go you would be in a decent position.

"So first and foremost, it's a must not lose game. And if you get the win, it's a great result that puts us in a great position.

"I think it will take the kind of performance we put on in Serbia and at Wembley in the summer.

"Austria are a top team. They have a lot of experience and really good players.

"They are well organised and it's going to take a top performance from us to take something.

"But we have shown in the past that we are well capable of that.

"So we will have confidence going into the game that we can get a result."