Michael Essien says Chelsea teammate John Obi Mikel, despite his problems with the Nigeria FA, can become one of the world's great players.

"I've not seen a young player like Mikel, I think he can prove one of the best in the world." says Essien. "He's so calm and full of confidence. He's unbelievable. He's really strong and tall. He's good. And it's like he grows every day . . . though I know how to deal with him."