Steven N'Zonzi
Steven N'Zonzi joined Sevilla from Stoke City in 2015 Getty

Sevilla are desperately trying to convince Steven N'Zonzi to sign a new deal with an improved €40m (£34.4m, $43,5m) release clause in order to ward off big European suitors. Estadio Deportivo claims that Chelsea sent a scout to Sevilla's encounter with Barcelona and the Andalucians are growing concerned about losing the former Stoke City midfielder during the coming January transfer window.

N'Zonzi moved to the La Liga side from Stoke City in the summer of 2015 for around £7m. The 27-year-old midfielder had a slow start to life in Spain but managed to turn around the situation playing a key role in Sevilla's march to the Europe League crown — beating Liverpool in the final.

As a result Leicester City were heavily linked with his services during the summer transfer window but Estadio Deportivo claims the player snubbed the Premier League champions to remain at Sevilla.

According to the Spanish publication Sevilla have since been in negotiations with N'Zonzi's agents to reward him with a new deal which would boost his salary as well as increasing his current €30m release clause to something around €40m.

However, both parties are yet to reach an agreement and the report claims Sevilla are anxious another club could exploit the situation to lure him away in January by activating his release clause.

Chelsea, Barcelona and Juventus had been linked with his services in recent weeks and Estadio Deportivo adds that a scout from the Blues was even in attendance at the Sanchez Pizjuan during Sevilla's 2-1 defeat to Barcelona on 6 November.

Antonio Conte is said to be interested in bringing him to Stamford Bridge to add more depth to his midfield. Yet, N'Golo Kante and Nemanja Matitc are excelling in his 3-4-3 but Cesc Fabregas appears to have fallen out of favour with the Italian boss.

Meanwhile, N'Zonzi recently failed to quash the speculations after admitting he was flattered to be linked with the likes of Chelsea.

"It's nice, it's good," N'Zonzi told L'Equipe, when asked about Chelsea's reported interest. "But I always say that this type of club is interested in other players too. I am not the only one. I know that big clubs are interested in many players.

"I focus on what I do at Sevilla. Until there is something concrete, we must remain professional. Some clubs were interested [in the close-season], but I feel good at Sevilla. I enjoy the game, the football, I like the way Sevilla play, I feel good in the city, with the fans and the club and I'm enjoying myself."