Didier Drogba is upset with Chelsea management over planned delays for a knee operation.

The Daily Mail says Drogba is angry with Chelsea because he feels he needs a knee operation to be ready for African Nations Cup duty, according to sources close to the striker.

Chelsea want him to carry on playing but the Ivory Coast star fears doing so will prevent his participation in next month's tournament.

Boss Avram Grant said: "If he can play, then OK. If he cannot and needs surgery, we will do it."