Guillem Balague looks at how Jorge Sampaoli and Samir Nasri are transforming Sevilla ahead of Sunday's clash with Barcelona live on Sky Sports.
Sevilla have been one of the stories of the season in La Liga. They sit three points off the top of the table having only lost one of their first 10 games, and on Sunday they can jump above second-placed Barcelona if they beat Luis Enrique's men at the Sanchez Pizjuan stadium.
They can approach the game with confidence. Sevilla lost their three-time Europa League-winning manager Unai Emery to Paris Saint-Germain in the summer, but their strong start under Jorge Sampaoli has fuelled talk that they are dark horses in the title race.
So what's changed? Well, 11 new signings have certainly helped, and Sampaoli's high-intensity, attacking playing style has also proved a good fit for a side who already played aggressively under Emery. The big difference, however, is that Sampaoli wants them to dominate the ball, too.
The stats show it's working. Their numbers for possession, short passes per game and passing accuracy have risen sharply from last season. In fact, Barcelona are the only team in La Liga to have averaged more possession.
"The key for us is to build our own identity," said Sampaoli earlier this season. "We cannot play scared, so we must seek to dominate the game and think about our rival's goal."
Sampaoli encourages his players to be brave with the ball, and it's having a positive effect. Sevilla are playing slick, passing football, and on-loan Manchester City midfielder Samir Nasri has been at the heart of it.
"Nasri is performing and showing how good he is," said Sampaoli last month. "He is a player at the height of his game, and he is getting us through matches."
With his sharp passing, positional flexibility and clever movement, Nasri typifies what Sampaoli wants from his players.
The former Chile manager is also changing things up in a tactical sense. Incredibly, Sevilla have used eight different formations in just 10 La Liga games this season. That level of tactical flexibility is unrivalled in the division, and their unpredictability makes them difficult to defend against.
The likes of Steven N'Zonzi, Vitolo and Franco Vazquez have impressed, but Nasri is perhaps the most important player when it comes to making the system work. From defensive midfield to left wing, the Frenchman has already lined up in four different positions this season, and he has excelled in every one.
The bad news for Sevilla is that Nasri is a doubt for the Barcelona game after sustaining a hamstring injury last week. His absence would be a big blow, and the stats show why.
Nasri's intelligent distribution is vital for Sevilla's possession-game - his passing accuracy is the highest at the club - and his dribbling ability is important when it comes to keeping the ball in tight spaces.
He's a goal threat, too. Nasri scored his first goal for Sevilla against Athletic Bilbao, and he added to his tally against Leganes. There was also an important strike against Dinamo Zagreb in the Champions League.
Without Nasri, Sampaoli and his trusty assistant Juanma Lillo would have to find new solutions. Barcelona will provide a big test of their credentials, but Sevilla have shown it would be foolish to write them off.