The timing is uncanny. In the same month as José Mourinho's arrival at Old Trafford will almost certainly force Ryan Giggs to leave his boyhood club, the review pages are filled with details of a new book recalling the tungsten-wire brilliance of Adrian Doherty, the Strabane natural who briefly vied with Giggs as the most promising youth player ever seen at the club.

In his idle moments, it must still be source of aggravation for Ferguson that he never got to realise his vision of Giggs and Doherty operating as the chief attacking torments on both wings for Manchester United in the early 1990s. The publication of Forever Young, a fine portrait of a deeply unlucky football prodigy by Oliver Kay, has rescued from obscurity a vital life story.

Michael Walker of this parish is among the football writers in England who couldn't quite forget the electrifying potential Doherty radiated in his brief spell at Manchester United. Doherty never actually played for the senior team but travelled with the squad on several occasions and was in such irrepressible form by March of 1991 that he was heavily expected to make his debut.

Arthur Duffy, the Derry Journal football writer, travelled to Old Trafford to witness the occasion. But it turned out that Doherty had wrenched his knee in a humdrum 50-50 tackle playing for the United A team against Carlisle United. He would later say that his knee "felt funny".

As it turned out, Ryan Giggs took his first Old Trafford bow that afternoon against Everton, while Doherty sat in the stand among a glittering hobbled cast which included Bryan Robson, Steve Bruce and Mark Hughes. To these senior men, Doherty was already part of the furniture: a funny-peculiar Irish lad with dazzling potential whom they nicknamed "Doc".

Nothing to worry about

Doherty told Duffy after that the injury was nothing to worry about but, in perhaps his only ever concession to envy, also admitted: “That should have been me.” Duffy chose not to print the observation at the time, feeling as most people did that it was only a matter of time.

But that was as close as Doherty got: the injury failed to heal, thieving him of a sliver of the speed with which he terrorised opposition wingers and backs, and in 1993 he aborted an attempted comeback with Derry City.

As it happened, football was just one of many strings on Doherty’s bow: even at Old Trafford, he was the purest form of free spirit: utterly oblivious to materialism, lost in song and poetry composition, beatnik in his fashion choices, an incessant guitar player and utterly out there in comparison to the narrowing dressing-room habits and interests.

What made Doherty’s story so compelling was that after being let go by United, he simply walked away from football, pursuing his song-writing and travelling where the wind blew. He was funny with an absurdist streak, carefree and almost never mentioned his past with United. In 2000, the day before his 27th birthday, he fell into a canal in The Hague one morning on his way to work. He couldn’t swim and died a few days later.

Some 16 years later, Kay has done Doherty and his family justice in saluting his brief but mesmerising time at Old Trafford. The human story is engrossing but what leaps out from the pages is the brutally thoughtless way in which aspiring young footballers were treated then.

Like old Hollywood, the reality behind the curtain was grim, even at a football club as famous as Manchester United.

For someone like Doherty, there was little attempt made to facilitate what was clearly a lively intellectual curiosity so he had to do so by his own devices. And at the heart of the book is the family’s understandable unhappiness at how what turned out to a cruciate ligament injury was handled.

A full year passed before it was decided to operate on the injury and it was January 1993 before he made his comeback. By then, the United training staff were excited by another winger from Northern Ireland, Keith Gillespie.

Even if Doherty sometimes dazzled contemporaries on mornings training alongside United’s fabled class of 1992, there was an increasing sense that those within the club had given up on the hope that he would recover. He was let go in March of 1993, just as the club’s first team went supernova.

There was no malice in how Doherty was treated but there was clearly no sense of protectiveness or a willingness to persevere with a youngster they had fought so hard to sign at the age of 14. The club was flooded with young talent: he was expendable.

Luminous

There is precious little film of Doherty playing football but the anecdotes from contemporaries like Giggs and Phil Neville are luminous in admiration and clarity. There is a sweet irony in the fact that while Doherty was all but forgotten in the rush of success which transformed United, he clearly remained a vivid figure in the minds of some of United's most celebrated figures – including Ferguson.

There is a haunting passage late in the book in which Michael Walker recalls asking Ferguson about Doherty in an interview at the Cliff in December 1999 and the manager, then at his most regal, rose from his seat and looked out the window at the training ground before telling Walker that he could still see the moment his protégé had been injured.

Maybe, in more enlightened times, the injury need not have defined his football life. Until it happened, it would have seemed more difficult for Doherty not to become a Manchester United star than to become one. It must be impossible for his family and friends not to feel that he should have been part of the cast of United stars that conquered England.

Doherty’s disinterest in talking about United once he left the club and his early death meant that there is no book of evidence on what he felt about his football life. Family, friends and old team-mates have provided the chorus and Kay leaves no stone unturned in tracing the Irish man’s scattergun life after United.

In a strange way, it reclaims Doherty as a burningly vivid presence within the United corridors during a turbulent time; an original who left an indelible impression on the most successful club manager in history and who didn’t even need to make a senior appearance to convince his peers that he was blessed with a rare football talent.

It should have been more than that, of course. But while the contribution of most football players pale and disappear in the years and decades after they leave the game, Adrian Doherty’s slender body of work has only begun to shine.