Arsenal coach Mikel Arteta and his Champions League final adversary, Paris Saint-Germain's Luis Enrique, share roots in Barcelona and an obsession with excellence, as their friendship turns to rivalry.
Saturday's battle in Budapest sets these two former teammates, and disciples of departing Manchester City coach Pep Guardiola, on a collision course.
"Pep has been a reference for all of us who want to play football in a certain way," said Luis Enrique, who followed in the Catalan tactician's footsteps by coaching Barca.
Arteta credits Guardiola with giving him the know-how to begin his own coaching career, having worked under him as an assistant at City for three years.
The trio crossed paths in Barcelona around the turn of the century in their playing days, before the younger Arteta departed, his path blocked.
In 2001 with Xavi Hernandez and Andres Iniesta emerging with him from La Masia, minutes were at a premium.
Barca had also signed Emmanuel Petit from Arsenal to join Luis Enrique and Guardiola in a congested midfield and Arteta was told to leave the country on loan to PSG.
"It was terrifying for me (and) for my family," Arteta, who was 18 at the time, later told Arsenal's website.
The Spaniard made 53 appearances over 18 months in Paris and shared a room with imposing defender Gabriel Heinze, now one of his staff at Arsenal.
"It was an experience that will stay with me forever, with teammates who shaped who I wanted to be as a player and ignited something in me to become a manager," he added.
Arteta signed for Rangers in 2002 and spent most of his career after that with Everton and then Arsenal.
While Luis Enrique's playing career and coaching career to date has thus far outshone Arteta's, that could start to change this weekend.
"Mikelito Arteta... I'm very fond of him," said Luis Enrique, whose team is more expansive and flowing than Arteta's.
"It will be very difficult but we believe a lot in our style of play and what we want to do."
Some might construe the 56-year-old's use of the diminutive as a mind game ahead of the final, bringing back the nickname he had for Arteta a quarter of a century ago.
In last season's semifinals, when they met, Lucho's PSG edged through.
BREAKING BOUNDARIES
As coaches, both Arteta and Luis Enrique arrived at clubs frustrated by underachievement and took them to what they craved.
While PSG have dominated in France for many years, they had never been able to fulfil their Champions League ambitions until Luis Enrique arrived.
Stripping away the fat, the Asturian's hungry young team shredded Inter Milan in last year's final to claim their first European Cup.
"He's a fantastic coach, the best coach in the world, but he is also an amazing person," said PSG president Nasser Al-Khelaifi.
It was Luis Enrique's second Champions League triumph, after guiding Barca to the trophy in 2015. Only four coaches have won more.
Arteta hailed his compatriot's "aura".
"The way he transmits the message, how convinced he is about what he does, and regardless of any opinion, he (sticks) by what he believes – I think that's a superpower," Arteta told Uefa.
Former PSG midfielder David Beckham said Al-Khelaifi told him Luis Enrique slept virtually "every night" at the training ground during his first season in charge, so obsessed was he with shaping the team's present and future.
That drive is also present in Arteta, who has poured himself into the job over the past seven years to revive the fallen north London giants.
Appointed in December 2019 with the team 10th in the Premier League, Arteta pledged to get Arsenal back in contention for football's "top trophies", and slowly proved himself right.
This season Arsenal ended a 22-year wait for the title and returned to the Champions League final for the first time in two decades.
The 44-year-old put faith in youth and, like Luis Enrique, cleansed the squad of stars who did not fit the culture he was building.
"We came digging, digging, digging and you have to keep digging because one day the gold is going to be there," said Arteta at the start of this season.
Built on clean sheets and control, the Gunners ground their way to glory, rather than overwhelming opponents like Lucho's PSG, although possession and positional play are important to both coaches.
"You can see Mikel Arteta is a leader... who has instilled a winning mentality," observed Luis Enrique.
Arteta already dethroned three-time Champions League winner Guardiola domestically this season and now faces another of Barcelona's old midfield masters, who is aiming to complete his own European hat-trick.