The 21-year-old has been in the headlines for a couple of years - and not just on the back pages. There is reason to believe he could be a throwback to the days when many of Scotland's finest footballers were creatures of fragile mentality, who thrilled and then self-destructed. Jim Baxter, George Connolly, Willie Henderson, Jimmy Johnstone were all such shooting stars, destined to burn out before their time. Ferguson, immensely talented, is the latest to have been ushered on to centre stage and so far he has shown nothing to suggest he can shoulder the combined weight of fame and fortune, not to mention a small nation's outrageously large expectation.
Ferguson has already been fitted with the handle, 'Duncan Disorderly', and although some use it affectionately it suggests a young man well acquainted with trouble. Already he has been fined by the courts for having butted a policeman (pounds 125), and punched and kicked a Hearts fan on crutches (pounds 200), and recently he was placed on a year's probation for another assault charge. Sherriff Charles Smith told him a prison sentence had been considered and that he was not presenting the proper image to youngsters.
The subject of the highest transfer fee ever between two British clubs was also advised to receive counselling regarding his alcohol intake. Clearly the authorities are not prepared to allow Ferguson much more leeway, and he knows he will have to tread carefully, especially now he is a player in Glasgow, a city whose football interest builds to a crescendo at Old Firm matches, the next of which is this coming Saturday.
Rangers, though, must first deal with this afternoon's League Cup final against Hibernian at Celtic Park. They will tackle this match without Ferguson, whose knee injury will restrict him to a watching brief for perhaps another month, by which time he will be ready to challenge seriously for a place in a first team which abounds with pounds 1m-plus players. In seven games for Rangers before injury struck, Ferguson failed to find the net, but it is his prowess in the air and his touch - so subtle for someone with a 6ft 3in frame - which make the Ibrox side believe they have the best young player in the country. But he must compete with the likes of Ally McCoist and Mark Hateley, the most potent strike force in top-class British football. The idea was that Ferguson would eventually replace Hateley, but the Englishman has been performing so well that the Rangers manager, Walter Smith, could not possibly drop him.
On his arrival, Ferguson was tried up front with Hateley while McCoist was recovering from a broken leg, but the partnership did not gel. Despite his cost Rangers are prepared to use Ferguson sparingly until the time is right to employ him on a regular basis. Smith points out: 'Liverpool were applauded for a system whereby they paid money for players and then put them in the reserves for a while. I'm trying to create a similar system at Ibrox.'
Smith is prepared to wait for Ferguson to mature, mindful of the fact that someone who can be dragged into scuffles in a taxi rank in Stirling and in an Anstruther hotel won't have to look far to find trouble in Glasgow. Rangers can only hope that Ferguson, whose offences were committed before he signed for them, accepts the responsibilities which come with his great skills.
Ferguson's rise has indeed been meteoric; he moved straight from Carse Thistle under-14s in his home town of Stirling to Dundee United when still no more than a lanky child. He made his first-team debut at 18 and scored 35 goals in 88 matches. While at Tannadice, Ferguson was often at odds with the Dundee United manager, Jim McLean. In one celebrated exchange, it was alleged that Ferguson was dropped from the first team and ordered to dig ditches at the club's new training ground because he had been holding out for better terms. Eventually the player conceded defeat and signed an eight-year deal. Rangers, however, sensed United were willing to part with their best player, and joined Bayern Munich, Leeds United and Chelsea in the chase for a striker who had already played for his country at under-21 and senior levels.
Although McLean, who is also United's chairman, insisted he would not do business with Rangers, they kept increasing their offer. Bidding opened at pounds 1.5m and, as it soared, it became too much for Bayern and Chelsea, and when Leeds went as high as pounds 3.25m, it seemed they had won. However, the Ibrox club's millionaire chairman, David Murray, a man accustomed to getting what he wants, took the offer to pounds 4m and suddenly McLean said yes. Murray could not back down and the deal was done.
United are now in the process of upgrading their ground, paid for in part by Rangers, who in return have an asset with attitude. If anyone can bring Ferguson to heel, it is Smith, but much will depend on the player himself. 'I can't speak about what happened to him before he came here,' Smith said, 'and I can only advise him. I can't follow him about everywhere he goes, but I think he realises what is expected of him on and off the pitch. Rangers still believe in him, but he has to show he is responsible.'
If he doesn't, Rangers could be left with another of the Scottish game's fallen idols. Even McCoist is campaigning on his behalf - 'Just give him some time to settle, to adjust' - but the doubts surrounding Ferguson are of his own creation. The biggest club in the country has given him the platform and it is now up to him.
James Traynor is football correspondent of the Herald, Glasgow