Chelsea bring in police over racist Twitter abuse of Mikel John Obi

• Incident followed midfielder's mistake against Juventus• Club condemn 'disgusting and abhorrent' tweetChelsea have condemned racist abuse of Mikel John Obi on Twitter, after the midfielder deleted his account.Mikel removed his profile from the social networking site less than 24 hours after his mistake helped cost Chelsea victory in the opening match of their Champions League defence against Juventus.Chelsea originally said it was entirely coincidental that Mikel, who claimed he wa...