Didier Drogba is on daily trial at Chelsea, it has been revealed.

The Telegraph says if he fails to work hard, Drogba risks becoming the squad's invisible man. Left out of the squad who prevailed 4-1 at a raucous Roots Hall, Drogba was allowed to train with the first team on Thursday but there is no guarantee that the striker will even be on the bench for Saturday's meeting with Stoke City.

Blues boss Luiz Felipe Scolari is adamant that he wants more effort from the Ivory Coast centre-forward, one of the players believed to be in the Brazilian's "35 per cent" effort rating at Manchester United on Sunday.

Chelsea sources stress that Drogba did not react angrily when informed by Scolari he would not be travelling to Roots Hall, and that the conversation was very much one way. Drogba, though, is known to be unhappy at seemingly being made the scapegoat for Chelsea's recent stuttering form.