Lionel Messi, Luis Suarez. Iconic European shirts coming together in front of a packed and eager stadium. In keeping with the tone of a competition organised by an American company, there will be glitz and glamour on show this evening in Dublin as Celtic and Barcelona get together in the International Champions Cup in the Aviva stadium.

Yet, while Celtic’s involvement in the tournament has offered them a lucrative sideline this summer, the real razzmatazz comes not in a cosy friendly but in the group stages of the UEFA Champions League. It is where the real riches – on and off the field – lie. As such, Callum McGregor, the Celtic midfielder, will look to use tonight’s meeting as a prelude to what could come later this season.

Tonight’s game may well open their eyes to what is required at this level. This is Barcelona’s first game in their pre-season schedule and it is expected to be a relatively skeletal squad, yet there will inevitably be lessons from Celtic to absorb from this contest. McGregor is keen to take them on board.

“The thought of playing against the Messi and Suarez, it excites you,” said the 23-year-old. “You see these guys playing in the biggest matches in the Champions League, El Clasicos. You watch them on the TV and now you are going to play them, test yourself against the best in the world. It shows you where you are at.

“This’ll be a good test for our fitness and the way we want to play. Hopefully, it’ll be a sign of things to come and we can just keep building. We want to play them in the real thing and that’s what we are striving for. I would hope we could face them in the group stages of the Champions League in a few months time, but we’ll have to wait and see.”

Ensuring that ambition is realised this season will, in part, be determined by what happens at Celtic Park on Wednesday night when Brendan Rodgers’ side play FC Astana in the second leg of their third round Champions League qualifier.

The Kazakhstan side may not hold the same glamorous allure of Barcelona, but given what is at stake it would be understandable for Celtic’s eyes to stray towards what lies in wait midweek.

The balance of the tie is in Celtic’s favour, yet a swift reminder brings to mind a similar scoreline against Maribor two seasons ago – a result that carried little weight when the Parkhead side were humbled with a 1-0 defeat in Glasgow.

“All of the boys are looking forward to it and it’s another good test, against the best players in the world,” said McGregor. “Games like this are ideal preparation for the Champions League matches. Last weekend, it was Leicester City before the first leg against Astana and now it’s Barcelona ahead of the second leg.

“It is tough opponents, going up a level. It’s about fitness and sharpness at this stage of a season and facing this level of opposition is great for that. It’s Barcelona’s first game and we’re a few weeks down the line, so we have to try and take the game to them and compress them, then we’ll see what happens.”

Celtic have shocked Barcelona more than once in the last decade, the most recent surprise coming at Celtic Park in 2012 on a night when Tony Watt stole the headlines. Comments from Lionel Messi this week appear to underline that theory that the Catalan side hold the Parkhead club in high regard – the striker claimed that Celtic belonged in the Champions League – and McGregor would love the chance to acquit himself well against the La Liga side.

“I think the last time we faced Barcelona and Tony Watt scored, I was injured,” he said. “We’ve played them a few times, but I wasn’t fit. This’ll be my first game at first-team level Barcelona always seem to hold us in high regard and, as a club, that is great to hear when big clubs and big players are saying that about you. It’s up to us to keep that going and do well against them.”

McGregor has featured in the last two competitive games under Rodgers – he did not feature in the starting line-up against Lincoln Red Imps in Gibraltar but played in the return leg and then against Astana last Wednesday.

He does offer am energy and efficiency in the middle of the park and he is desperate to show something again this evening which cements a position in Rodgers’ side.

“It’s still early doors and every game for me is about doing something which keeps me in the side, keeps me going forward,” he said. We know there is a big squad and the gaffer has said that everyone is playing for their place.

“Everybody has that competitive edge anyway, but having that incentive can only drive the standards up in training and in games. I’ve had a couple of small chats with the manager and everything has been positive, in terms of how he wants us to play and the way he sees me playing.

“It’s positive and you just try to keep it going.

“You just focus and try to show as much as you can, which, hopefully, will keep you in the plans.”