Perhaps greater than any other concern that Rangers supporters hold over their team travelling to Celtic Park without their backing is that they might not have the requisite minerals to handle it.

To have 60,000 Celtic supporters baying for their blood, Brendan Rodgers’ side flying out of the traps at them, and to have it within them to meet fire with fire.

A man who has never been accused of lacking such courage or pride in defending the Rangers jersey certainly hopes the current crop can find such fortitude from somewhere before Sunday, because he is sure they are going to need it.

When Graeme Souness is asked how he would handle such a situation, you can almost physically see his heckles rising. In fact, for a second it looks as though he might literally lick his lips.

“I’d relish it, bring it on,” Souness snarls.

“See if we can squeeze 80,000 in. F**k, yeah.

“Don't ask me, ask some of my teammates. The bigger the game, the better I was. The bigger the challenge…bring it on.”

It is a cry of defiance that sums up the man, and the character of the Rangers sides he took charge of. Souness concedes that Philippe Clement does not have the abundant talent at his disposal that he enjoyed in the late 80s and early 90s, but he would accept no excuses if the men in blue wilt this weekend.

“The Rangers players now have to have that mentality,” he said.

“If you're going to go there and play and be at your best, you have to believe you're going to be, you know, it's going to be all about me today. If seven or eight of them think that, then you've got a great chance, not a good chance.

“It is a unique football match. Celtic, especially at Parkhead, will come after you like they've lit a fire. That's never been any different at Parkhead. So, you've got to weather that storm.

“You hear up and down the country at every football match that the last thing the manager or coaches would be saying to the players is we've got to play, start the game, make sure you start right.

“If ever there was a game you have to start right, it’s an Old Firm game at Parkhead for Rangers players. You must start right.

“I had big players who dealt with that without a problem. Terry Butcher, Richard Gough, Mark Hateley, Ray Wilkins. I had men who could deal with that. And that is the price on the ticket if you play for an Old Firm team. You've got to deal with those pressures.”

What Rangers fans would give to have Souness leading them out the tunnel on Sunday.

“I wish I could still play,” he said.

“And try and stay on for 90 minutes!”

Within the current laws of the game, that may seem unlikely. But it did seem likely for a while last year that he would be coming back to Ibrox in some capacity at least, with an advisory role mooted.

He participated in the process that ultimately ended with Clement being appointed as manager – more on that later – but a formal boardroom role never materialised. And it is unlikely to in the future.

“In terms of going back, that boat has sailed for me,” he said.

“I am now in a great place in my life. I still like to work. I’m still very active. And I just count my blessings every day because I see people that I've played against, or I've played with.

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“Some are no longer with us, and some are suffering with dementia. Or some form of it. And I'm just blessed. I just feel I've been so fortunate.

“Look, we're not talking about Rangers right now, but there's room for ex-players to be involved in football clubs. Just to offer them a bit of what the fans are feeling, what their football opinion is on stuff.

“But at Rangers I'd like to think they're listening to everything that Phil Clement is telling them about the footballing side of things now.

“Because I believe he knows his stuff.”

Did he always believe that, though? It was well documented that Clement was not the horse Souness ultimately backed in the race to replace Michael Beale, after all, with Frank Lampard his choice to step into the office he himself once occupied.

“Let me clear that up,” he said.

“I was big on Frank. I'll tell you why I was big on Frank.

“Philippe was the best interviewer. He was very impressive with his presentation. And then he turned around and said, ‘well I've not really done this before.’ Well, he must have practised in front of a mirror, because he was more than good, he was excellent.

“Frank was attractive to me for two reasons. He's very well off, his life is in the south. Whatever job he gets now is his last chance saloon.

“And equally as big as that, I asked him in an interview ‘how friendly are you with Man City and Chelsea?’ Because I'm thinking, ‘we don't have any money, we’ll get players on loan.’

“So, that's why I slightly leant towards Frank. But I think we've got a very good manager now.”

Maybe so, but Clement goes into his fifth Old Firm encounter with three losses and a draw to his name so far. Is that a concern to Souness, and does it add pressure to a Rangers manager’s shoulders when he can’t get the monkey of a win over Celtic off his back?

“I don’t know!” he counters with a grin.

“Listen, I was lucky here because I had a time when we could buy some of the best players that Britain had.

“For Philippe he'll be richer for the experience of last year. I saw two Old Firm games last year. I saw the 2-1 game at Parkhead when the Rangers went down to 10 men. I also saw the cup final, and I didn't think there was a lot between the teams.

“In fact, I thought the Rangers should have won the cup final. But that counts from nothing this year. The fact that they have dominated the league in the last decade or so means nothing.

“On match day, the names on the team sheet don't mean anything. It's who turns up on the day and performs. Who enjoys a wee bit of luck.

“What special players do something special. That's what decides these things.”

Whatever gap there is between the sides then, it may well be the gap between the ears that proves most important.

Martin O'Neill and Graeme Souness were guests on The Warm-Up, the essential William Hill SPFL preview show.  Watch their exclusive Old Firm episode by clicking here.