A first full season in charge at Everton had resulted in a 10th-place finish in the Premier League, though there was no sign of the Italian doing anything other than planning for the future at Goodison Park during the close-season.
Then, however, Zinedine Zidane left Madrid and everything changed. In a flash, Ancelotti is now back in the Spanish capital six years after Los Blancos said 'thanks, but no thanks', ending a first stint in charge that spanned two eventful years and included a historic Champions League triumph.
"What did Ancelotti do wrong? I don't know," club president Florentino Perez said when announcing Ancelotti's exit in 2015. The pair parted ways as work colleagues but the personal relationship remained intact, allowing them to come back together again.
Perez opted to dispense with Ancelotti despite him delivering 'La Decima', as well as the Copa del Rey and FIFA Club World Cup. He also boasted the best success rate of any head coach to be at Madrid for a minimum of 50 games at 74.8 per cent, winning 89 of his 119 games. That number eclipses Jose Mourinho (71.9 per cent) and comfortably Zidane, too (65.4 per cent).
However, there was no league title the first time around. Now the former Milan, Chelsea and Paris Saint-Germain boss gets another crack at conquering LaLiga, with Los Blancos aiming to knock noisy neighbours Atletico Madrid off their perch.
Attack the best form of defence
There will be some familiar faces in the dressing room to greet Ancelotti upon his return, but also some notable absentees from the squad he left behind.
Across his previous reign, Madrid averaged 2.7 goals per game. That number was aided by the presence of Cristiano Ronaldo, the club's all-time leading scorer now taking up residence in Turin.
In LaLiga, Ancelotti's side led the way in terms of goals, getting 104 in 2013-14 and then 118 in the following campaign, eight more than a Barcelona squad led by Luis Enrique that clinched a famous treble. His Madrid averaged 18.1 shots per game – the same number as Zidane's side during his first stint – with a conversion rate of 14.9 percent.
The Frenchman's time between January 2016 and May 2018 sees similarities in terms of attacking numbers to the period under Ancelotti, the common denominator being they both had the irrepressible Ronaldo to call upon.
Zidane's comeback saw a different Madrid, one that attempted more passes – they averaged out at 596.5 per game, compared to 576 previously – but dipped in terms of attacking output, their goals-per-outing number dropping from 2.6 to 1.8.
There was an over-reliance on Karim Benzema in 2020-21, the French striker scoring 23 times in the league. No other Madrid squad member reached double figures, Casemiro next on six. Well, Gareth Bale did, though that was during a year on loan at Tottenham.
Ancelotti may struggle to match the offensive numbers of his previous version of Madrid, but he is acutely aware of what is expected from his team.
"The history of this club forces you to play well and have a spectacular game. I believe that football has changed in these years towards a more organisational approach, but the idea of Real Madrid must remain the same," he told the media.
The same Ancelotti, only different
"This is not the same Carlo Ancelotti from six years ago. I have six more years of experience. Positive and negative. I was very happy at Everton and I have grown as a person and as a coach."
Those were the words of the man himself at a news conference on Wednesday which covered a number of topics, including Sergio Ramos' future, the potential arrivals of Kylian Mbappe and Ronaldo, plus the open letter released by the man he has now replaced.
Ancelotti's appointment at Everton was seen as a coup for the Merseyside club and while there were high points during his reign, including a long-awaited win at Anfield (one of 11 away victories in 2020-21), but inconsistent results at home sunk hopes of securing European football, with a resounding 5-0 defeat to Premier League champions Manchester City ultimately bookending the 61-year-old's tenure.
Still, Ancelotti averaged 1.53 points per game, better than any other previous Everton boss to have at least 10 games in charge, including David Moyes (1.50) and Ronald Koeman (1.47), who – if reports are to be believed – will be staying on at Barca, meaning the Toffees will have been coached by both men in charge for next season's Clasico contests.
However, it is Atleti who are the top team in Spain. Diego Simeone's side faltered with the line in sight, but still managed to finish first in a title race that had seemed set to be a procession at one stage during the campaign.
LaLiga is the solitary title in the top five European leagues to so far evade Ancelotti, who knows better than anyone that not even on-pitch success is always enough to keep you in one of the biggest jobs in football.