Manchester City’s crucial Premier League clash with Chelsea carries with it several fascinating sub-plots and arguably the most fascinating of them all will come off the pitch.
For not only will it be the latest collision between two of English football’s most successful sides of the past decade.
It will also cast further positive light on just how far the Premier League has evolved through the compelling shape of rival managers Pep Guardiola and Maurizio Sarri.
The pair – along with Tottenham’s Mauricio Pochettino, Liverpool chief Jurgen Klopp and Unai Emery of Arsenal – in many ways represent the very embodiment of the modern face of the Premier League.
Fearless, innovative and forward-looking, both in their thinking and tactical approach, that phalanx of managers has not only helped transform the outlook and philosophy of their respective clubs but also redefined the landscape of the English game in myriad positive ways.
In terms of Guardiola and Sarri specifically, in addition to Sunday’s keenly-anticipated Etihad clash, the two are also preparing to lock horns again later this month when City tackle Chelsea in the Carabao Cup final.
What provides added intrigue looking ahead to the two games is the huge mutual admiration and close bond of friendship that exists between the pair.
And that rapport is all the more fascinating given that the respective backgrounds of the two could hardly be more diametrically opposed.
Pep famously enjoyed a wonderful playing career as a cultured midfielder, becoming the heartbeat of a Barcelona side that during a stellar 17-year spell at the Nou Camp yielded six La Liga titles as well as a Champions League and numerous other pieces of silverware.
Sarri, in sharp contrast, originally embarked on a fascinating career arc that originally saw him earn his living from working in the banking sector while he played football as an amateur.
The proud son of Naples only took up a full-time career in football at the age of 40, having set out on his fledgling managerial career back in 1990 with USD Stia before going on to further his development with spells in charge of 16 other Italian clubs before taking up the helm at Napoli in 2015.
Pep meanwhile made a seamless transition from pitch to dugout, helping inspire Barcelona to even greater heights at home and in Europe as manager before going on to enjoy similar success while in charge at Bayern Munich and now City.
Yet despite their diverse backgrounds, there are common threads of identity and touchstones in the pair’s approach and belief as to how football should be played.
Both tend to favour a 4-3-3 set-up, encouraging a high pressing game allied to precise, rapid passing and a commitment to playing high-octane attacking football.
Sarri, firstly at Napoli and more latterly at Stamford Bridge, sets his side up with a designated playmaker – Jorginho is his go-to man of choice – playing in front of the back four in a system some have come to dub Sarriball.
Guardiola meanwhile deploys Fernandinho as the Blues’ crucial holding midfielder though the Brazilian also has licence to roam further forward and weighs in with more than his fair share of crucial goals.
There may be subtle differences in approach but fundamentally the duo’s founding touchstones and guiding principles remain the same.
Attacking football, high energy in attack and defence and a commitment to entertain and score goals.
There’s also no mistaking the mutual respect and admiration for each other’s achievements.
Back when City were paired against Sarri’s Napoli in last season’s Champions’ League group fixture, Pep made no secret of his huge admiration for the job undertaken by the Italian.
After our 2-1 victory at the Etihad in October 2017, Pep hailed Napoli as ‘maybe the best’ team he had faced in his career.
Such is the friendship and respect, the pair met up last summer, in the company of the great Arrigo Sacchi – a key touchstone for both – shortly before Sarri swapped the challenge of southern Italy for west London.
And after his unveiling at Stamford Bridge, Sarri expanded on his own deep admiration for the body of work and attacking philosophy overseen by his Catalan counterpart.
“He (Pep) is a class act, a champion, a genius, so it is difficult to explain what his insights are,” Sarri said of Guardiola.
“I think that getting 100 points in the Premier League (as City did last season) is an extraordinary feat. Something that cannot be repeated. We are talking about a genius.”
Another characteristic that the pair share is their unswerving belief in how the game should be played. Both are adamant and steadfast in their vision and guiding belief.
Quizzed earlier this month as to whether he would be tempted to alter and refine his principles after a series of frustrating results for the Londoners, Sarri couldn’t have been clearer in his response.
“I don't mind, because I am a dreamer. I want to play my football. If I’m here, it's because I am a dreamer,” he declared.
In the same vein, Pep was just as crystal clear about his opinion on a change of approach after our losses to Crystal Palace and Leicester during the Christmas period.
"That is not going to happen. It has not happened in the first years and it is not going to happen," Guardiola declared.
"Why should I change? Because I lost two games? No way. That is not going to happen."
Guardiola and City got the better of Chelsea in August’s Community Shield season curtain-raiser.
Sarri then enjoyed the first win of his professional career over Pep when Chelsea defeated the Blues 2-0 at Stamford Bridge in early December.
All of which means the scene is set for two huge encounters starting this Sunday.
With City chasing the Premier League title and Chelsea seeking to strengthen their grip on a top-four spot, the stakes are high.
One thing remains crystal clear though.
Regardless of the result, the bonds that bind Guardiola and Sarri will remain