It was supposed to be Pep vs Jose. That was the rivalry that we all expected to ignite the Premier League when both managers took the reins at their respective Manchester clubs back in the summer of 2016. With their caustic clashing of ideologies and verbal skirmishes still simmering from their time in Spain we duly sat back and awaited the fireworks.

That didn’t quite go to plan of course with Mourinho’s time at Old Trafford proving to be something of a damp squib and, while Guardiola was transforming Manchester City into a brilliant and dominant conception, the Portuguese scowler concentrated his acerbic ire on his board and the media.

If this was – and remains – a missed opportunity we didn’t have long to mourn what might have been, though, because flying up on the rails was Liverpool.

Jurgen Klopp and the Reds fit the bill nicely in offering up an epic duopoly with City to rival that of Arsenal and Manchester United back in the day, or Chelsea and Manchester United in the 2000s or indeed pretty much any side that rose to prominence during the long reign of Sir Alex Ferguson.

In creating a modern, box-office rivalry the supporters have certainly played their part with antagonism resplendent across social media, while on the pitch the two teams have been breath-taking and formidable. Since the start of last season they have accrued a combined 261 points from a possible 294 to this point – a staggering feat – and more pertinent still in that timeframe Manchester City and Liverpool have won every single trophy – both domestic and abroad – that at least one of them have been involved in.

As for the respective managers, a resumption of their competition in Germany has engrossed one and all with particular fascination deriving from their different approaches to the game. One is heavy metal, the other jazz.

Unquestionably Jurgen Klopp and Pep Guardiola are two of the most charismatic and captivating men to prowl a Premier League touchline. Unquestionably Liverpool v Manchester City or vice versa is now the biggest game in English football. In fact it could be said that it’s missing only one key element, and with that it could truly be elevated into the pantheon of all-time unmissable rivalries: mind games.

Remember them? They were all the rage back around the turn of the century. A manager would walk into a press conference, play some psychological chess at the expense of an opposition coach. So the theory went, when the coded barb reached said opposition coach he would be so crippled with insecurity his subsequent team-talk that Saturday would be shoddy and substandard.

His team would then go on to lose and we would all champion the first manager as a Machiavellian genius; a Mr Miyagi-type who could probably shape-shift in his spare time so other-worldly was he. The ‘victim’ would be cast as a chump, outwitted in the public eye.

It was all utter nonsense of course but we needed something to entertain us before broadband. In reality it was always, without fail, just Ferguson or Mourinho or Wenger being petty or petulant or indulging in a moan, and we would all project onto it a deeper meaning and an impact that simply didn’t exist.

“Club X gets all the breaks. It’s not fair,” complains Manager Y, like an underdeveloped brat. Club X then fail to win the title a few months later. “Manager Y is a genius,” we all exclaim. “He has subtly influenced the referees into thinking twice about giving Club X free-kicks and more so has parachuted doubt into the opposition dressing room.”

It was a different time. We weren’t very bright back then.

It all began famously in 1996 when Sir Alex Ferguson suggested that Nottingham Forest would not try as hard against Newcastle United as they did against his own side and with both Uniteds locked into the closing stages of a fiercely contested title race this prompted Kevin Keegan to emotionally unravel live on air.

In hindsight though it is perfectly clear that Keegan is a brittle man at the best of times and here he was under extreme duress. Frankly, Ferguson could have saved himself a few words and simply said, “Boo. Pass it on” to have a similar effect.

Later, with Liverpool threatening to reclaim their perch in 2009 Ferguson had a whine or three about perceived favouritism from the authorities and this directly led to Rafa Bentiez’s ‘dossier rant’ and once again Ferguson was heralded as a mind games master thinking two steps ahead.

Yet he could have no way of knowing what would transpire. He was simply having a moan just like he always had a moan when things were not going exactly his way.

In between these heightened examples were a multitude of jibes and whines – let’s not forget Mourinho disgracefully calling Wenger a ‘voyeur’ – from a multitude of managers under pressure and all were legitimised by erroneously being considered as mental manipulation.

Thankfully, in the 18 months or so in which we have seen Liverpool emerge as a redoubtable rival to Manchester City we have seen no evidence of such silliness and this despite the fact that Klopp and Guardiola are asked about the other on an almost daily basis.

There is a healthy mutual respect there and respect too for the fans who now recognise ‘mind games’ for what they really are: an insult to our collective intelligence.

That is until last week when Pep Guardiola – peeved at discovering that his rivals had once again scored a late winner – petulantly described £34m Liverpool star Sadio Mane as a diver. It was uncharacteristic of the Catalan, that needs saying, but beyond that there is little excuse for his comment.

Because on no level do such words lead to anything positive. They make him – and by extension City – appear bitter, thus giving Liverpool an open goal to the moral high ground. They have taken to that high ground this week in their defence of the winger, as they are entitled to do. It has also allowed them to come across as the good guys.

With City heading to Anfield this weekend the timing too was so blatant in its intentions that a five day old kitten could see through it. Is the referee now going to be hard-line on the Senegalese attacker? Or will he be determined not to look swayed by a pretty rubbish attempt to get into his head? The latter is more likely.

More than all this though is that Guardiola’s petty and unnecessary words was a throw-back to an era when we knew little better. We do now. We’ve evolved. We’ve grown up.

Until the Manchester City boss sharpened his claws ‘mind games’ had been consigned to a naïve past. That’s where they should stay.