Blues boss Jose Mourinho confirmed that neither player is expected to be back for Sunday's clash at Old Trafford as Chelsea remain in the grip of a goalscoring crisis.
Lampard (thigh) and Drogba (knee) contributed more than 50 goals last season and Mourinho is bemoaning their absence.
"I am getting no good news from the medical department," he said. "I don't think they will be back for Sunday.
"The news is not getting worse but I want them to tell me the players are ready to train. But there is no good news."