Branislav Ivanovic has revealed Diego Costa has quickly become a leader at Chelsea.

Ivanovic says off the field, Costa is a warm and humble character.

Speaking to Chelsea's official website, Ivanovic said: "[Costa] knows how to control himself very well.

"He never sleeps in the game, he's not quiet, he wants to be a star, and he wants to be the player around which everything happens in the game.

"It's good for the team when he's working and you can see he is always trying to win duels and look positive on the pitch. He is set up like this for the team, it's his style.

"He's a very nice and funny guy. He likes to make jokes and I think when he improves his English he'll have even more influence in the squad."