And so the final movement in Keane's opera of a playing career will begin in the lowest key imaginable. Broadwood rather than Broadway. A shoebox of a ground fit to hold just over 8,000 frozen souls, the pitch hemmed in by stands on only three of its sides.

Strange though it may seem, he's not the biggest Celtic story of the week in Glasgow. He's barely even the second biggest.

Chris Sutton's move to Birmingham City and his pointed expression of gratitude towards Martin O'Neill but not towards Gordon Strachan has been exercising people's two-pint punditry since Wednesday. And the news that John Hartson and Stephen Pearson are doing the rounds on someone's camera phone singing along to 'The Fields Of Athenry' at a function in Letterkenny . . . but not, they stress, joining in with the more objectionable refrains . . . has almost allowed Keane's debut to slip in under the radar.

Almost.

Because, of course, low-key is all relative. Where the rest of the world will reckon it's tuning into little more than an afternoon of amateur dramatics today, Clyde will never again feel as bright a burning spotlight. There was talk during the week of the club erecting a 15-foot high fence on the fourth side of the ground to prevent whistling passers-by dawdling for a look while out walking the dog but by Friday, the idea had been binned. Bad enough not to have had enough tickets to go around the folk who'd helped cover the pitch each evening; stopping them peering through the wire would have been beyond the beyonds.

Anyway, they've enough to be getting on with without the added headache of erecting a fence that size. Mother certainly never told John Ruddy there'd be weeks like this.

Ruddy is the club's public relations director, the grandness of whose title doesn't quite accurately portray a job which some weeks amounts to little more than making sure a photographer from the Cumbernauld & Kilsyth Advertiser is present for a prize-giving night. But he's earned his salary and more this week.

Requests for accreditation have flowed in from journalists from 12 different countries for this game. As well as the major national newspapers from Scotland, England and Ireland, there have been applications from Holland, Belgium, Germany and beyond in Europe, some from America and even one from Australia (although Ruddy had a hard time believing it was genuine).

The possible debut of Chinese defender Du Wei has brought interest from Beijing and such was the demand from Japan that Celtic playmaker Shunsuke Nakamura personally took care of it that two tickets from his player's allowance went to members of the dozenstrong contingent who are permanently based in Glasgow to document his every move.

And all that's before radio and television have their space cleared. As Ruddy says, "It's fun and exciting and what have you, but there's just no chance I'll be able to fit everybody in."

Certainly not into a press box more used to dealing with single than triple figures. Consequently, some of Britain's sharpest-suited football writers will become reacquainted this afternoon with the reason their computers are called laptops as they sit among the punters. Considering some of the things written about him down the years, Keane would be forgiven a smile at that one.

There's been a sense in Glasgow all week, though, that this is a bigger deal for the outside world than it is for those who'll be around long after the cameras, laptops and accents have left. Maybe it's to do with the amount of time that has elapsed since he signed or maybe people simply have better things to be doing with their lives but Roymania hasn't quite taken a grip of the city yet. There are no huge displays bearing Keane's name in the Celtic shop in Sauchiehall Street (although the deal that brought him to Glasgow is said to be comfortably washing its face in shirt sales). There's no sign of 'I, Keano' in the theatre listings, no Gift Grub window display in HMV.

Even Celtic's training has had to be curtailed a touch, half their training pitch having been found to be unplayable for Strachan's last pre-game session due to a Thursday night frost. There have been no bells, no whistles, no fanfares this week. No baying crowds at Parkhead, no swarms of autograph hunters surrounding him after training. All of which is much, you'd have thought, as Keane would want it and about as far removed from the Bernabeu as it's possible to get.

A similar atmosphere prevails . . . more so, indeed . . . on the other side of the green/blue divide. In the Rangers shop on (naturally) the far side of Sauchiehall Street, questions of Keane are met with a blaze of indifference. "We couldnae give a shit aboot him, " says Jim, a 19-year-old Blue as he hands over a fiver for a set of Rangers golf tees. "We'll see him in February, won't we? It's too early in the year to be botherin' wi' that shite yet."

Jim is not alone. A straw poll conducted along the staunch Rangers pubs of Paisley Road West . . . The Clachan, The Grapes and The District . . .

elicits nothing more than the early-January shrugs of men just trying to get over the Christmas and New Year in peace, thank you very much.

"You wouldnae do a story on Rangers agin' Peterheed, would you?" is about the most worked up anyone manages to get. It is decided that, on balance, Tribune readers probably wouldnae be into such a piece.

He'll start today, the bits and pieces of speculation as to his match-fitness or lack thereof notwithstanding. Stilian Petrov's injury has, for the moment, saved Strachan biting a bullet that probably doesn't look particularly appetising to him. There'll come a time, though, when Petrov, Keane and Neil Lennon are all present and correct.

Strachan has sworn that he won't change his formation and that he hasn't bought Keane as a centre-half. Trouble may be stewing, like good strong tea.

But if there is, Strachan gave little indication of it when he sat down with the press in the Jock Stein Suite on the third floor of Celtic Park at Friday lunchtime. Petrov's injury he passed off as proof that signing Keane was the right thing to do because, "you never have your perfect team available to you and if you don't believe that, just look at what's happening to poor Graeme Souness". It was only when he was asked if he thought Keane's arrival would banish any thoughts of complacency in the squad that he became at all animated.

"People are looking at that the wrong way, " he said. "Roy's not exceptional in holding himself to a high standard. Professional footballers don't get here by accident. There are hundreds and hundreds of players like Roy Keane out there. They don't care if they're playing in front of 50,000 people or in a five-a-side in training. They know that when they're playing, they want whoever's watching to walk away thinking, 'I've seen a player out there'.

"So to think that Roy is unique in the way he approaches the game is wrong. Roy's attitude to the game is spot on but so are many others'.

He's not come here to get rid of complacency. These players don't have that attitude."

Convincing stuff, even if there was a touch of well-hewould-say-that about it.

Secretly, however, Strachan must be pleased that Keane's registration could be processed over the Christmas break, making this the game all the attention would be focused on. Clyde are a side made up mainly of cast-offs from the SPL and are making strides in Division One. Without the debut of Keane to sharpen the mind, there's a chance . . . albeit a slim one . . . that this could have been a cup tie for Celtic to trip over. As it is, it shouldn't present a serious problem.

Keane's presence has another knock-on effect, of course. In the Clyde dressing room, there'll be an opposing midfielder who may have to hold teacup far away from saucer for fear of a giveaway rattling sound. Steven Masterton turned 21 just last Monday.

Tallish for a midfielder, locals say he's clever with possession, if a bit dainty in the tackle. In the 14 games he's played for Clyde since joining last summer, he hasn't yet picked up a yellow card. Singled out by Strachan on Friday as a fine passer who could hold his own at a higher level, he doesn't seem the type to try to make a name for himself by clattering into Keane straight off the bat. His manager would have had no reservations were it him lining up but Graham Roberts was telling anyone who'd listen all week that his boy would be fine. At the very least, he should find himself at the head of the queue when swapping shirts.

In the end, it will be a relief for all concerned to get the first one out of the way. Those expecting a crowd-pleasing cruncher of a first tackle will probably be disappointed although those who've taken the 5-2 about Keane being shown a yellow card could well be in the money given how card-happy Scottish referees have been lately . . . another subject which has rivalled Keane for column inches all week.

Whatever happens, as with every move he's made this past decade and a half, the eyes of millions will be on him.

The end starts here.

SCOTTISH FA CUP THIRD ROUND CLYDE v CELTIC Broadwood Stadium, 1.00 Live, Sky Sports 1, 12.00