The Tartan Army will be there, more than 50,000 of them; the Boys in Green will be there, in numbers surpassing the 3,300-ticket allocation; there will be alcohol, there will be Celtic Park, there will be Rangers-Scotland fans. There will be the East End of Glasgow; there will be the football tension of a crucial European Championship qualifier. And all on a Friday night.

As the Scotland fanzine, Epistles, Bullshit & Thistles, has it: "Is that not just a recipe for drunken disaster spilling over into trouble?"

Alan Nelson is the Partick Thistle fan and veteran Scotland watcher who wrote that line. This week Nelson sounded less concerned that trouble on Glasgow streets next Friday is inevitable, though he still called the scheduling “crazy”.

The selection of Celtic’s ground as a venue for a potentially pivotal Scotland home game – against a team in green managed by Martin O’Neill – appears strange to many Irish eyes, especially as in the absence of Hampden Park, Ibrox would have been a less comfortable experience for Ireland all round.

Without incident

But for monetary as well as policing reasons it may have suited the Scottish FA to stage the previous home game, against Georgia, at Ibrox. Georgia are hardly the draw to Glasgow the Republic of Ireland are and Celtic Park’s capacity is 60,000, Ibrox’s 51,000.

And while there will be relief should Friday night pass off without incident, there will be those in Scotland who said they told us so, because there is an opinion the Tartan Army has changed – again.

By the World Cup of France ’98, the image of the marauding Scots tearing up Wembley had been superseded by the kilt-wearing Tartan Army in ‘see-you-Jimmy’ wigs. Scots now meant bonhomie.

“I think it started before France ’98,” Nelson said. “At Spain in 1986 and Italia ’90, there was a conscious movement away from violence and heavy drinking – well, away from violence.

“I think some were a bit ashamed of what had gone on in the 1970s and ’80s, plus there was the ban on English clubs because of their hooliganism. There was a sense of: ‘That’s how the world sees us too’.

“Self-policing came in but it’s gone beyond that now with the Tartan Army having a children’s charity – in Warsaw last month they visited an orphanage and took over practical gifts.”

A further change is the composition of this “Army2. As Ronnie Johnston said: “In the 1960s and ’70s I’d have thought 60 per cent of Scotland’s support was Rangers. It’s flattened and reduced ever since. It’s a guess, but I’d say around only a quarter of the support now comes from the Old Firm.”

Johnston, 59, a member of two fan-ownership groupings at Rangers, first saw Scotland play in 1966. From 1969 he did not miss a Scotland match on these islands until after Wales away in 1985, the day Jock Stein died in Cardiff.

Eight years

But Johnston has not been to a Scotland match for eight years.

“For Rangers-supporting Scotland fans, Celtic Park is probably not an issue,” Johnston added, “because I think that many, many Rangers fans have simply stopped supporting Scotland, and I’m one of them.

“I didn’t like the way the Scotland support was turning – the jovial Tartan banter was over the top. Then there was booing of Rangers players – Barry Ferguson and Allan McGregor, more recently Ian Black, and there was a perception that Rangers players were not being picked. That is a quite a strong feeling among a significant chunk of Rangers’ support and many did not go to the international at Ibrox for that reason. That was anything but a Rangers occasion.”

Like Johnston, Nelson was reluctant to be definitive about something as varied as a fanbase, but Nelson said: “There’s a bit of a myth that Scottish fans don’t come from the Old Firm, because they do, but maybe that’s lessened with less Old Firm players in the squad, and fewer from Rangers. There’s quite a lot of Anglo-Scots in the squad.

“Like the Irish fanbase and the Irish diaspora, Scotland’s is worldwide. Within Scotland it runs from north to south, east to west. You hear accents from Aberdeen, the Borders and the Highlands, all over.

“At Ibrox, v Georgia, yes, there were empty seats, but I think that was down to pricing. Celtic Park will be better because it has a shape more like Hampden Park, a similar feel to it.”

Since last Saturday’s draw for the Scottish League Cup semi-final, the Old Firm is back on the radar – if it ever went away. There was a visible divergence in the Scottish independence referendum with Vote No banners being unveiled at Rangers and Celtic fans holding Yes flags. But there was a “Yes Rangers” group, too, and for Glasgow to have become a “Yes city”, some Rangers fans must have voted that way.

With the heightened awareness of nationalism, Scottish National Party membership has surged since the recent referendum – leaping from 25,000 to 83,000 – but the 2014 Tartan Army isn not simply the athletic wing of the SNP. Then again, Flower of Scotland replaced God Save The Queen as the team's anthem in part because Scotland football fans' booed GSTQ. Colin Weddell thought of the independence vote of 1979 and said: "Maybe Flower of Scotland means something different to some fans today."

Famous photograph

Weddell was 24 then, and the subject of a famous photograph from the Argentina World Cup a year earlier. Weddell was in Mendoza when Archie Gemmill scored his epic goal against Holland. On Wednesday in a bar in Edinburgh, Weddell, a Hearts fan, looked at it again.

“There was no real Tartan Army then, just disparate groups of friends,” he said. “There’s still quite a mix – it’s not simply rampant SNP supporters.

“Interestingly, the day after the Georgia game there was a ‘Hope Against Fear’ rally in George Square in Glasgow. The crowd looked the same as the night before – saltires etc. There’s always been a nationalism to Scotland games, but local football politics tend to dissipate.

"I don't think the atmosphere will be hostile next Friday. Humour dominates – against Norway in Bordeaux at France '98 we were singing: 'We're the famous Tartan Army and we're here to save the whales.' What we miss is being part of that, being part of the carnival. That to me is bigger than anything. It's a shame that only one of Scotland and Ireland fans are likely to make it through."