Chelsea midfielder Mikel John Obi says visiting West Ham has lost its fear factor.

Chelsea will be playing West Ham at their new London stadium for the first time in the fourth round of the competition tonight.

Obi told the London Evening Standard: “West Ham's new ground is very good but I think it's why they have suffered in the League. It is a big ground, a good pitch and I think clubs go there to express themselves. In a way, every team that goes there feels that both teams are playing away from home.

“In contrast, playing at the Boleyn Ground was very intimidating. The stands were very close, the fans were right there and the pitch wasn't that big. West Ham knew how to play on that surface, they were used to it. You could hear some of the things their fans were saying to you and it was unnerving.

“But in a big stadium like the one they have now, you can't hear things. It is only a matter of time before they get used to it and they did just beat Sunderland.

“I just hope they don't show what they can do against Chelsea."