It is one of the oldest cliches in football, but as far as this fixture goes? It really is taken literally.

So applicable is ‘no such thing as a friendly’ to Celtic vs Rangers that when one was actually arranged in Australia last year, it caused an international incident. There may be nothing tangible at stake when these old rivals meet at Ibrox on Saturday, but it’s always been about much more than that, anyway.

Callum McGregor knows that better than most, and will be hammering home the message that although the Premiership trophy will be returning to Celtic Park in just a few weeks, the champions cannot cruise across the city basking in the glow of their second successive title.

Never mind the fact that Ange Postecoglou is determined to sustain momentum heading into June’s Scottish Cup final – fans on either side simply do not allow anything other than full throttle on these occasions. If there couldn’t be a friendly thousands of miles from home, there’s hardly going to be one in Govan, is there?

“I don’t think so!” McGregor said. “There’s no such thing as a dead rubber in these games. There’s always something to play for.

READ MORE: Celtic boss Ange Postecoglou headlines Manager of the Year shortlist

“You are playing for pride, your supporters – you are playing for the badge. These players understand that, which is part of the reason we’re been so good in these games.

“It’s another good test for us to go there with no supporters, go in there with a siege mentality and try to get a positive result.

“We can go there full of confidence as we got there as champions and we can show our personality.

“They are playing for pride as well. They will want to dent us. 

“We need to go in with a collective mentality, where we know everyone will be against us. We have to use it, harness that energy, and try to turn the crowd against them a little bit.

“The game plan won’t change. We'll be aggressive and try to get as much as we can from the game.

“We’ve been like that all season. It’s been highly competitive in training because everything has always been on the line.

“You don’t have that level of success if you’re taking days off. The mentality from the manager is we are on it every single day as hard as we possibly can and play every game like a cup final.

“That will be similar from now until the end of the season. There’s a lot still to play for.”

There will be no Celtic fans in attendance at Ibrox as the clubs continue to stand miles apart on the, seemingly eternally, thorny issue of away allocations. By now, both teams will be as used to playing without a travelling support as with, and McGregor is confident he and his team-mates will relish deploying a ‘siege mentality’.

READ MORE: Why The Sound of Silence will be music to Liel Abada's ears at Ibrox

The midfielder believes this is the ideal fixture with which to refocus after a potentially distracting title celebration – he might even earn himself another cup of tea afterwards.

“It’s good to have that siege mentality and understand everyone is against you,” he said. “It can bring out the best in players and hopefully that will be the case on Saturday.

“It will be tough. When they are up and the crowd is up, it’s a difficult place to play.

“We will need all aspects of every game we’ve played this season to get the perfect result.

“It’s probably the perfect game for us after just securing the league. The focus is right on it again because there’s an expectation and a demand.

“I had to wait for my cup of tea last week but it was great. If you ask any player, that’s the kind of scenes you want to be involved in and the kind of memories that will last long after you have finished playing.”

Celtic can still complete a world-record eighth domestic treble if they beat Inverness Caledonian Thistle at Hampden next month, and that would mean the creation of yet more memories for the 29-year-old. If they do, McGregor will become the first player in history with five domestic clean sweep to his name, something he says – in typically understated fashion – would be ‘a nice personal achievement’.

“You look at how many domestic leagues there are around the world,” the Celtic captain said. “It doesn’t really matter what level you’re at, to have that consistency and that hunger to win and win again is something that drives me.

“To have that number of trebles would be really special but I don’t think you get there unless you have the mindset that you want to be as good as you can be.

“Every single day you need to push yourself and it becomes a combination of everyone else doing the same. When you start out, if you’re looking for things like that, it can seem a million miles away, but this has crept up on me.

“And in terms of our next success, the cup gives us that opportunity and we want to get the trophy back to Celtic Park. In turn, that would give me a nice personal achievement as well.”

Elsewhere on his list of achievements for the campaign, McGregor has surpassed 400 Celtic appearances and picked up his 50th Scotland cap. He has been in and around the good times almost his entire career, but could this season end up topping the lot?

“It has the potential for sure,” he said. “When you rhyme off those milestones it makes me feel good and proud of what I have achieved. But again, it’s all underpinned by being in a good Celtic team.

“It’s very much a collective effort and if we can get over the line in the cup final then that will add to what’s gone before and make it a really special season for the club and for the players as well.

“The players have gone above and beyond to bring this club success and that’s what’s expected. To go and deliver it, however, is another thing.”