Ahead of kick-off at San Siro on Thursday night, Leonardo Bonucci will put on his usual playlist, which always ends with the song 'Faded' by Alan Walker.
The repeated refrain 'Where are you now?' will resonate with Bonucci even more than usual, with the AC Milan captain having been left in a state of shock by the sudden death of his Italy team-mate and good friend Davide Astori on Sunday.
He remembered how many laughs they had shared together, how often 'Grande Asto' had supported him on and off the field.
“Come on, Leo, do a sweeping pass like only you know how’ was what you kept repeating to me during tactical training sessions," he revealed in an open letter to the Fiorentina centre-half.
"With that smile that never ended and that made it clear how much goodness there was within you."
Bonucci unsurprisingly struggled to process the news that his friend had suddenly passed at just 31 years of age. He was in no state to play a game of football and he knew he was not alone in that regard, given Astori's popularity among his peers. He immediately called Inter defender Andrea Ranocchia to discuss calling off Sunday night's derby at San Siro.
Ranocchia was in total agreement, meaning that even before the Italian Football Federation (FIGC) had confirmed that all Serie A games would be postponed, both players had already decided that the game at the Giuseppe Meazza would not go ahead.
Instead, Bonucci and Milan will return to action in the Europa League, against Arsenal. It was a game that the former Juventus defender had been looking forward to almost as much the derby, a chance for the Rossoneri to show the rest of Europe the remarkable way in which they have been transformed since the appointment of Gennaro Gattuso as coach.
The former midfielder hasn't just revived Milan, though, he has revitalised Bonucci, who had been left looking like a broken man following his arrival from Juventus for €30 million last summer.
Indeed, the song 'Faded' strikes a particular chord with the 30-year-old because he can relate to sense of loss and confusion which follows heartbreak.
"Under the bright
"But faded lights
"You set my heart on fire
"Where are you now?
"I'm faded, I'm faded
"So lost, I'm faded, I'm faded
"So lost, I'm faded."
Bonucci parted company with Juventus after the complete collapse of his working relationship with Bianconeri boss Massimiliano Allegri.
He embraced Milan's offer to become part an exciting new project with open arms but as Vincenzo Montella struggled to integrate 10 new players into his first team, Bonucci was a shadow of his former self.
He had immediately been installed as captain, as he was considered the ideal man to unite a relatively inexperienced dressing room - yet he was struggling to keep himself together.
He began to fear that he had made a huge mistake in leaving Juventus for Milan. He had known that swapping the Champions League runners-up for a team that had no played in Europe's top competition since 2014 would be a "step back" - but he didn't think that the Serie A season would prove so tough, either for Milan or himself.
"To be honest, at the start I did wonder why I had done this and if it was worth it,” he told Sky Sport Italia.
"My performances on the field were not those of the real Bonucci because mentality can change everything."
And that is where Gattuso came in. The former Milan midfielder was installed as Montella's successor on November 27 and made an immediate impact on Milan’s dressing room.
"He made each individual feel important," Bonucci enthused. "From his very first speech, it was understood that the music had changed."
Gattuso also made it clear to Bonucci that he was trying too hard.
"At the start, I was in the wrong and focused too much on everything that was around me,” he explained, “thinking I had to rescue the club, but it's a team effort and about working together.
"I took some of the responsibility off my shoulders and found myself again. Gattuso did help me in that sense too. He took on a lot of that responsibility.”
Gattuso didn’t just lift Bonucci’s morale, either. He also made a crucial tactical tweak that changed the course of both the player’s and the club’s campaign.
Montella had understandably assumed that Bonucci would be best positioned in the middle of a three-man defence, as he had been at Juve, but Gattuso promptly paired the Italy international with Alessio Romagnoli.
Milan may have taken some time to settle - they won only one of Gattuso's first four games at the helm - but they are now unbeaten in 13 matches, culminating in them last week reaching the final of the Coppa Italia after a penalty shootout success over Lazio at the Stadio Olimpico.
Bonucci and Romagnoli were once again immense in the Italian capital and it is now 584 minutes since Milan last conceded a goal in any competition.
“When you play a lot with the same partner you get to know him and you know where you can help him, and vice versa," the Viterbo native explained.
“Alessio has made a great improvement since the beginning of the year. He has found faith in himself and now he is doing well."
Of course, one could say the same about Bonucci. He has got his self-belief back. He no longer feels lost. He has found himself again. More importantly, though, he knows where his good friend is now.
Ciao Grande Asto, era così che ti chiamavo quando ci incontravamo, per una partita che ci vedeva avversari o per un raduno in Nazionale. Un sorriso e un abbraccio di quelli veri, una persona leale, onesta e umile. Quante volte abbiamo riso, scherzato, gioito insieme. Quante chiacchierate a tavola seduti accanto, o lungo il corridoio che a Coverciano porta alle camere, o in campo, e anche in camera. “Dai Leo sventagliamela come sai” era quello che mi ripetevi ogni allenamento durante la tattica. Con quel sorriso che non finiva mai e che faceva capire quanto di buono c’era dentro di Te. Te ne sei andato a giocare lassù e so che lo farai sempre con un grande sorriso. Quello che ti ha sempre contraddistinto. Sei un grande amico mio. Mancherai. Leo
"You have gone to play football up there and you’ll do it with the same big smile,” he wrote on Sunday. “The smile you always had."
Some lights never fade out.