Chelsea boss Antonio Conte has moved to end speculation over Diego Costa's future.

Costa has been linked with talks over a return to Atletico Madrid in the past 48 hours.

But Conte insists his talisman is 'very happy' and will play a pivotal role within his squad ahead of his debut Premier League season.

Conte explained: "Diego Costa is our player, he's a fantastic player with fundamental importance.

"He's very happy and is working hard."