Ali v Frazier, Magic v Bird, Federer v Nadal: when the dust has settled on their great careers, Mourinho v Guardiola could come to be as recognisable as any of the iconic sporting rivalries.

What makes their decade-long duel unique is that it’s happened when neither have been athletes. There have been great coaching clashes in the past, across all sports, but due to the uncertain and erratic nature of the job often they occur across short moments in time.

Mourinho and Guardiola, however, have been almost intrinsically linked over the last 10 years. Drawn together by fate, maybe, in a romantic sense, but also because over that time period they’ve been the best two managers in world football.

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Attack v defence, possession v direct football, development v spend; there are clichés that mark their divide and while all are not necessarily true once the nuances are explored, they remain two very different managers with opposing thoughts on the game.

Whether it’s by unseen or practical forces, they meet for 22nd time at the Etihad Stadium on Sunday. Our friends at Football Whispers detail their great rivalry ahead of the Manchester derby.

Guardiola edges the head-to-head 10-5 with six draws but Mourinho has the greater trophy count of 25-22, and April’s 3-2 win for United is still fresh in the memory, Paul Pogba’s double delayed City lifting the title.

That it was the Portuguese who momentarily poured cold water on City’s march to the title is symbolic in itself as Mourinho has been Guardiola’s bete noire ever since he took up coaching full-time in 2007.

An intertwining past

Although they didn’t compete against each other until 2010, Mourinho and Guardiola’s relationship dates back to the mid-1990s when the Portuguese worked as a translator for Sir Bobby Robson at Barcelona with the Catalan a distinguished midfielder for the club.

Mourinho has since admitted the pair were “close” and he still keep a framed picture of them embracing after Barca’s triumph in the 1997 European Cup Winners’ Cup.

Mourinho departed the Camp Nou in 2000 to focus on his coaching career, one that would lead to significant and ground-breaking success with Porto and Chelsea, sewing the seeds of the cult of the manager which is now prevalent in football.

Guardiola maintained his playing career until 2006, as Mourinho was reaching the apex of management at Stamford Bridge, but it wasn’t long until their paths first intertwined again.

After leaving Chelsea in 2007, Mourinho was interviewed for their vacant post in Catalonia following the exit of Frank Rijkaard. He even suggested he’d appoint Guardiola as his assistant. But the Barca board chose Guardiola as their man and so began his own ascent to the top, revolutionising the club and restoring its sense of identity.

Managers clash

Sweeping all before them in Spain and Europe, the team of Messi, Xavi, Andres Iniesta, Dani Alves and Gerard Pique became the best team in the world. Meanwhile, Mourinho had taken over at Inter. An Italian giant but a club who had failed to make a notable impact in continental competition. That was to change in the 2009/10 season.

Drawn against Champions League holders Barca in the semi-finals, the Blaugrana appearing a strong bet to become the first to defend the trophy, Inter won the first leg in Milan 3-1 and then produced a defensive masterclass in Catalonia; they lost 1-0 but the aggregate scored was sufficient.

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It was vintage Mourinho, playing with 10 men for more than an hour after Thiago Motta’s sending off, the Nerazzurri proved spoilsport and pragmatism trumped idealism. The illusion of Guardiola’s team being unbeatable was shattered.

A rivalry bigger than two men

That victory, coupled with Inter completing the job and claiming the Champions League crown, was enough to convince Florentino Perez to bring him to Real Madrid. The Los Blancos’ president concerned at the potential monopoly on success being created by Guardiola.

The two seasons they matched-up in La Liga cemented their rivalry but for all its entertainment, was as notable for its unpleasantness: Clasicos were ridden with bad blood, play-acting and ill-feeling, Neither team covered itself in glory.

Off the field, Mourinho and Guardiola exchanged barbed comments and although by the time the latter had walked away from Barca he held the better record over the Portuguese, he famously confessed to friends his opponent had, “won the war”.

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That was because the vitriol had led him to seek solace in a sabbatical before moving to Bayern Munich where he enjoyed further domestic success, while Mourinho made a triumphant return to Chelsea by winning the Premier League title in 2015.

Bar their meeting in the European Super Cup of 2013. Their rivalry was somewhat on hold, and subsequently cooled, but then the great Premier League managerial influx of 2016 occurred and as Mourinho joined United, so Guardiola followed to City.

Manchester – the new battleground

Since being paired in the same city in England – a scenario almost inconceivable during their days at Madrid and Barca – there has been a thaw in relations; a mutual appreciation of each other. Out of necessity, almost, as Guardiola was left drained by his experiences at Barcelona.

City’s rise under the Catalan coach has only exacerbated the frustration felt around Mourinho’s role at United: Guardiola has combined style with success, while the Portuguese’s stubborn pragmatism has brought some silverware but few lasting memories.

They share common characteristics of competitiveness, relentless attention to detail and remarkable stamina in their hunger for success, which has resulted in their longevity as coaches at the very summit of football.

And it’s those traits which means Sunday’s encounter and and 23^rd meeting between the two, which the second derby scheduled for March 16, are unlikely to be the last of an enduring rivalry.

*all odds subject to change