It is odd to think of Maurizio Sarri as a coming power and Jose Mourinho as a fading force, given Manchester United's manager is four years younger than Chelsea's boss.
But Sarri's postponed entrance into elite football after a career in banking gives him a peculiar freshness at the age of 59.
Mourinho had that when he first arrived on the scene more than a decade ago at Porto then Chelsea.
Even as he was winning the Champions League in 2004 he still stood as an outsider to the elite, having started out as PE teacher and translator.
He felt the need to tell us he was a Special One such was the circumspect.
So as the pair prepare to face for the first time it is worth remembering just where they came from how that has fuelled their time in management.
Mourinho before football
Having seen his father Felix win one Portugal cap, Mourinho tried to become a footballer himself but gave up when realising his limited abilities and pursued coaching instead.
While studying for his degree in his early 20s he taught PE at Escola Secundaria de Alhos-Vedros, a town just south of Lisbon.
He is described as being very good, strict but hard-working, and popular among the girls in his class.
Mourinho coached at Vitoria de Setubal, Estrela da Amadora, and was a scout at Ovarense before, in 1992, he became translator for Bobby Robson, who had been appointed at Sporting Lisbon and needed a local to interpret his instructions to players.
The pair struck up a brilliant relationship, moving together to Porto for two years and then Barcelona in 1996.
Success followed and Mourinho stayed on when Louis Van Gaal took charge, gradually becoming more prominent. He would translate press conferences and plan sessions, leaving in 2000 to become manager in his own right at Benfica.
Sarri before football
As a player, Sarri was a centre-back at amateur level and never played professionally, instead working as a banker for Banca Monte dei Paschi di Siena in Tuscany.
Attached to the international department, he was a foreign currency trader and travelled Europe – to London, Zurich and Luxembourg.
The same summer as Italia '90, he began coaching, starting with U.S.D. Stia 1925 and taking in a whole host of small local clubs.
But in 2001, as Italy prepared to adopt the Euro, meaning his position was not a valuable as before, Sarri decided to leave his well-paid nine-to-five office job to embark on the profession that really excited him.
Sarri led Sansovino to the fourth tier but a lack of contacts meant he had to wait a long time to get on the famous Supercorso at Coverciano, Italy's elite coaching school in Florence, rather than skip the front of the queue.
So his route into management was delayed years. He did not reach Serie A until he was 55.
Mourinho's time as a manager
Despite recent travails, Mourinho will be remembered as one of the managerial greats.
One of only five managers to win the European Cup with two different teams, he also has the rare achievement of lifting titles in England, Italy, and Spain (as well as Portugal).
He upset the continent with Porto, changed the landscape of English football with Chelsea's back-to-back Premier League victories, and delivered a masterclass at Inter.
His time at Real Madrid was attritional but still yielded La Liga in record-breaking fashion and has even kept winning silverware at Manchester United, with the Europa League or FA Cup.
He gets justified criticism for the sniping style he now implements and a lack of clarity on the pitch, but for all the impact made by Jurgen Klopp or Mauricio Pochettino, neither yet has a trophy to show.
Sarri's time as a manager
After taking the plunge into management, Sarri has worked his way up from the lower tiers of Italian football.
He got Sangiovannese promoted to the third tier in 2004 and reached Serie B when he was appointed by Pescara the following season.
With his 17th club, he finally reached the top flight. He led Empoli to Serie A in 2013-14, becoming known as 'Mr 33' at the club because he allegedly thought up 33 different plans for set-pieces.
In June 2015, Sarri joined the club of his city of birth, Napoli, replacing Rafael Benitez, who left after missing out on Champions League qualification.
His style of possession-play and high pressing quickly gripped and reinvigorated the likes of Marek Hamsik, Gonzalo Higuain, and Jorginho.
Napoli went close to winning Serie A in each of Sarri's three seasons, finishing second, third, second, behind winners Juventus and won huge plaudits for performances. Manchester City boss Pep Guardiola is a major admirer.
