There’s something about Sevilla, Vitolo says. He is the latest in a long line of players they bought cheaply, €400,000 in his case, turned into an international, won trophies with and, in all probability, will sell for a huge profit. Atlético Madrid and Premier League clubs are among those contemplating his €35m (£30m) buyout clause. “At other teams, performances drop when they sell, but at Sevilla it’s always gone well,” the Spain winger says.

Led by the sporting director, Monchi, this is the club that sold Sergio Ramos, Dani Alves, Julio Baptista and the rest, over €250m of talent, and still completed the most successful decade in its history, winning nine trophies.

Now Sevilla may be enjoying the best year of all, and “enjoy” is the word.

This was not the way they expected it to go. In the summer of 2013 Sevilla sold Jesús Navas and their top scorer, Álvaro Negredo, and the following season won the Europa League. The year after that they sold their captain, Ivan Rakitic, and won the Europa League again. And the year after that, they sold Aleix Vidal and top scorer Carlos Bacca, and still won the Europa League.

Last summer, they did it again: they sold their top scorer Kévin Gameiro, to Atlético but that was just the start. Twelve more players departed, including the midfield lynchpin Grzegorz Krychowiak, and so did Unai Emery, the coach who took them to those three European titles and masterminded Paris Saint-Germain’s destruction of Barcelona in midweek. Such sustained success is in marked contrast to the fluctuating fortunes of Wednesday’s Champions League opponents, Leicester City.

Yet even for Sevilla, it had seemed like a step too far: 13 players out, 11 players in, some of whom are yet to have the impact they hoped, and more than just a change of coach, a change of model.

Emery’s replacement was Jorge Sampaoli, who rejects the “shift in paradigm” where athleticism is all that matters, lamenting the loss of “art” from the game, players becoming “mere functionaries”. Bringing him in was a revolution; it was also a risk.

“We made the impossible possible some time ago,” Monchi says. He thought the time was right to be bold, but had doubts. He warned the board they could be “in trouble”, that things might not go well – at least to start with.

Six months later, Sevilla stand second in La Liga after beating Eibar 2-0 on Saturday night having completed the best primera vuelta in their history. At that point, every team has played every other team: Sevilla beat Real Madrid, beat Atlético Madrid, and lost just 2-1 to Barcelona, having overwhelmed them in the first half.

In October, they broke a year-long run without an away win, and although it was early and not yet convincing, pieces still to fall into place, more wins followed, the performances getting better and better. Now they are playing arguably the best football in Spain.

“We thought the adaptation would be slower,” Monchi says.

Sampaoli, too, says he did not expect his team to be this well-placed, this soon. He had talked about a “process” that takes time. Results reinforced that process and performances followed surprisingly swiftly. After the victory over Real last month, Zinedine Zidane was asked if Sevilla could win the league. “Of course,” he said. Asked why, he replied simply: “You’ve seen them.”

Well, quite. Sevilla’s players believe the league is probably beyond them – Real Madrid’s and Barcelona’s resources dwarf theirs – and the Champions League, where they emerged from a group with Juventus, Dinamo Zagreb and Lyon, may offer better opportunity. But they do not lack ambition; their coach will not let them.

Sampaoli, a tattooed bundle of energy, racing back and forth on the touchline as frantically as his team, wants to always attack. He talks about ilusión – hope, desire, enthusiasm – while another word he uses a lot is someter. It doesn’t translate well, but it’s conquer, subjugate, impose, subject; it is what he wants his team to do to the opposition. Asked to define his approach, he says: “Don’t be scared. Don’t wait. Think more about their goal than your own. Want the ball. Go for it.”

His assistant, Juanma Lillo, a man Pep Guardiola counts as a mentor, is the perfect partner: both men are enamoured of attacking, creative football, while close to the players, but Lillo’s commitment to positional play compliments and tempers Sampaoli’s desire to see his side become a stampede. “Unai wanted to attack but he was very concerned with the tactical system and ensuring we didn’t concede many goals,” Vitolo says. “With Sampaoli it is totally different: he wants his team to dominate every game, to score lots of goals, whoever it’s against.”

Sevilla are doing just that – and with some familiar faces. The Leicester fans who arrive at the Ramón Sánchez Pizjuán stadium – one of Spain’s great footballing experiences – on Wednesday, will remember the men in the middle but not quite like this. Brought from Stoke City and on loan from Manchester City respectively, Steven N’Zonzi and Samir Nasri may be La Liga’s two outstanding players this season, Messi apart. Sampaoli described N’Zonzi as “an octopus” and Nasri as the man who gives the team “oxygen”.

“One of the things Sevilla has is [what they do with] players who are very good footballers but who for whatever reason haven’t been at their best,” Vitolo says. “The club give them affection, make them feel important, appreciated, and have always been able to get the best out of them.”

Nasri is a good example. Players arrive and they are revived; players leave and Sevilla survive.

“If you know anything about football, you know Sevilla have taken lots of players back to the top,” the 29-year-old Frenchman says. “I knew this was the right place for me.”

He was the right player for them, too, and in his preferred position at last. No longer on the wing, he is theoretically a deep-lying playmaker but has freedom to move, often the furthest forward of the midfielders and just as often the furthest back, always close to the ball. He completed a competition-record 145 passes in the 1-0 win at Dinamo Zagreb.

“Nasri could play anywhere because of his quality,” Vitolo says, “and for the way Sampaoli wants us to play it’s helpful for him to be one of the two pivotes: he brings the ball out, carries it to the forwards.”

As for Sampaoli, he says: “Nasri is like a player from a different era. He has that amateur’s spirit where you want to enjoy the game.”

His spirit, in other words. Nasri is enjoying it. At the Sánchez Pizjuán, they all are. “I’m obsessed with people leaving the stadium with a smile on their faces, having seen a team play with no inferiority complex and no fear,” Sampaoli says.