Exactly what Pep Guardiola wants to achieve in the rest of his football career, only he knows. But surely he has missed a trick by choosing to manage Manchester City over their local rivals United.

Considered by many football betting pundits and football figures to be the world’s best coach, the 45-year-old has already accomplished more than most of his peers can ever dream of – two Champions League titles, La Liga three times, the Bundesliga twice (soon to be three, surely), two Copa del Reys, the German Cup and the FIFA Club World Cup on three occasions.

However, there remains a sense of doubt in some people’s minds about Guardiola’s credibility in that he has never had to pick up a club by the scruff of the neck, shake it up and restore it to former glories. The groundwork was already in place at both Barcelona and Bayern Munich.

The same is true of Manchester City. At this stage in mid-February, we do not know how many trophies they will win in Manuel Pellegrini’s final season before handing control over to Guardiola, but feasibly it could be a historic four.

Even if the answer was, say, two, parallels could still be drawn with when Guardiola arrived in Germany in 2013 after Jupp Heynckes had taken Bayern to the treble which included the Champions League – and the Spaniard is still trying to replicate that feat.

In weighing up who is top of the coaching tree, there are those who would rather point to Jose Mourinho’s achievements over the last dozen years in that he has truly made a difference to the clubs he has managed, with the possible exception of Real Madrid where he ‘only’ won La Liga once in his three attempts and never took them to a Champions League Final.

But the ‘Special One’ turned Porto into European champions from out of nowhere, in both spells at Chelsea he made them Premier League winners and at Inter Milan secured the Serie A title in both seasons and also guided them to the treble including the Champions League in 2010.

Next up for Mourinho may well be a summer arrival at Manchester United, which looks a club tailor-made for one of his restoration jobs to turn them into winners again following three disappointing seasons after Sir Alex Ferguson’s retirement.

The Red Devils are a club crying out for the right managerial appointment having been taken backwards by David Moyes and not improved from that situation to any great extent by Louis van Gaal, unless there happens to be a miraculous improvement during the rest of this term.

United must have wanted Guardiola, because who wouldn’t? His stock is higher than that of any other coach in world football and he does not have the ‘baggage’ that Mourinho has accrued in flitting from one job to another, in some cases having left under a cloud due to his provocative persona.

At this stage football tips pundits do not know if United left their bid too late and Guardiola had already given his word to City, but the inside word appeared to be that pen was not actually put to paper until fairly recently.

Instead, rather than accepting United’s overtures, it appears likely that Guardiola simply fancied teaming up again with his former Barcelona colleagues Ferran Soriano and Txiki Begiristain, who now run the show day-to-day behind the scenes at City on behalf of owner Sheikh Mansour and chairman Khaldoon Al Mubarak.

And, of course, the Abu Dhabi United Group have a bottomless pit of money for Guardiola to splash on players, as long as it abides by Financial Fair Play rules of course.

So Mourinho and Guardiola, two former bitter adversaries from their Real Madrid and Barcelona days, could find themselves working in the same city next season, perhaps even living as neighbours in the Cheshire countryside.

It will be fascinating to watch their rivalry unfold, especially in the Manchester derbies. But from Guardiola’s perspective, in terms of legacy, he would potentially have had much more to gain from being in the home dugout at Old Trafford.