Yaya Toure conceded he is "worried" about how Napoli's partisan crowd might fire up their players in Wednesday's Champions League clash with Manchester City.
The Premier League pacesetters beat Napoli 2-1 at Etihad Stadium on October 17, but Napoli showed plenty to suggest they will be an even tougher opponent on home soil.
City have started the season well, but so have Maurizio Sarri's men, as they sit top of Serie A with 31 points after 11 matches, and are playing some of the most eye-catching football in Europe.
But in the Champions League Napoli have just three points from as many matches, compared to City's haul of nine, meaning the game will take on extra importance for the hosts.
And Toure is expecting the home fans to create a hostile atmosphere for City, the midfielder having been involved when they went to Naples and lost 2-1 in November 2011.
"The thing that impressed me most was the crowd," Toure told Gazzetta dello Sport.
"The San Paolo is a stadium which doesn't leave you indifferent, even as an opponent. Support like Napoli's strengthens a team.
"As a City player I'm not intimidated by it, but I'm worried by the way it fires-up the home team. In times of difficulty, fans like the ones in Naples can be decisive.
"This is an important game for us, which we must face with the right attitude. The atmosphere at San Paolo is an added problem."
Toure has regularly been linked with moves away from City in recent years, particularly to Italian clubs, and he did not rule out potentially heading to Serie A in future.
"I've had several contacts with Italian football in the past," he said. "But then I followed different and important paths like Barcelona and Manchester City. But never say never in life."