Peter Beardsley has always been a man of contradictions. As an immensely gifted footballer regularly dubbed a genius by team-mates, he was very much a dressing‑room outsider. As a coach, he represents an awkward amalgam of expansive Pep Guardiola-style tactical vision and a narrowly old‑fashioned mindset.

On the pitch Beardsley cut a thrillingly anarchic, creative and improvisational figure who, by joining the dots between midfield and attack, somehow invariably succeeded in also being a quintessential team player. Off it, though, a man who sometimes gave the impression he would have been happier playing in an earlier era never seemed afraid to stand alone.

Perhaps instructively, the shuffling, teetotal, Geordie creator with the pudding bowl haircut never really appeared “one of the lads” during those late 20th century days and rarely courted peer group popularity. Where some with a fraction of his talent swaggered, Beardsley’s off-field gait and general head-down demeanour was faintly apologetic and determinedly humble. If balls, cones or bibs needed collecting he always volunteered while, after matches, the winner of two league titles and an FA Cup with Liverpool, as well as the holder of 59 England caps, could often be spied helping staff load kit skips on to the team bus.

Few stars can have disguised their ego as heavily but observers at Newcastle United suggest this anything-but-synthetic public humility coexists alongside a passive-aggressive coaching persona which has arguably contributed towards one of the club’s greatest players being placed on gardening leave from his job as the under‑23s coach during an internal investigation into alleged bullying and racism.

Newcastle’s Yasin Ben El-Mhanni, a 22-year-old Londoner of Moroccan heritage, has accused Beardsley of bullying and is supported by written submissions from five team-mates. Beardsley is also said to have made an allegedly racist comment to an African academy player. In a statement issued through his solicitor, Beardsley – who will be 57 next Thursday on 18 January – vehemently denies all allegations.

Potentially the most damaging is Beardsley’s alleged – “you lot should be good at this” – comment when a couple of African players struggled with climbing apparatus at “Go Ape” during a squad outing to the Tyneside adventure playground. He is understood to adamantly maintain this was a general reference to the entire group of fit, young, supposedly agile footballers, and had nothing to do with ethnicity.

If Beardsley the player – a blend of David Silva and Andres Iniesta – would have been good enough to have played for Guardiola’s Barcelona, his coaching career has been less gilded. In habitually eschewing the usual methods of winning young hearts and mind – charm, humour, sports science and psychology among them – Beardsley is viewed by some as a rarely-satisfied perfectionist with limited understanding of younger players lacking real talent or the sort of consummate commitment and professionalism which characterised his own playing days.

This, after all, is a man who as a schoolboy growing up in Newcastle used to routinely carry out shopping errands for his parents with the ball at his feet. “I never touched it with my hands, not even in shops or crossing roads,” he has said, recalling those days of holding carrier bags while shoulder dropping and shimmying his way past pedestrians while dribbling along pavements.

“Peter was different from everyone else and there were some snide comments about him,” his old Liverpool team-mate John Barnes has said. “But he’s the player I most enjoyed playing with. He was crucial to my success.”

Beardsley will argue his penchant for delivering quietly issued but sometimes scornful put-downs to young footballers is character building but a clear frustration with perceived underachievers is evidenced by accounts of his pausing training to pull individual under-23s off the pitch and issue public dressing downs.

His mood has probably not been helped by the alarming shortage of players making the transition from the under-23s to Rafael Benítez’s first team and he has proved surprisingly thin-skinned when journalists have criticised his side’s sometimes poor performances.

If some youngsters have been inspired by the sight of Beardsley side-footing long-range volleys with astonishingly unerring accuracy during training, others have felt belittled.

It is telling that during Hatem Ben Arfa’s time on Tyneside, he and Beardsley became soul-mates. While Ben Arfa, a richly gifted, maverick forward, watched admiringly as the older man showed off extraordinarily training ground touch and technique, the coach denounced the Frenchman’s critics.

Beardsley’s other champions – and there are many loyal Newcastle academy graduates who believe his brand of tough love has been the making of them as footballers and people – talk of a man who goes the extra mile to maximise the talent of those displaying promise and desire.

A Premier League inquiry cleared Beardsley of bullying allegations brought by youth players in 2003 but personality clashes with senior figures partly explain why he took a three-year break from coaching Newcastle’s junior sides from 2006. One of Glenn Roeder’s first acts on becoming first-team manager that year was to instigate Beardsley’s shift to an ambassadorial role.

The grim determination which saw Beardsley overcome teenage rejection by Newcastle and a subsequent failure to make Manchester United’s first-team ensured he quickly mapped a route back into junior coaching. It did not take long for the old contradictions and paradoxes to resurface.