The Sun says Drogba is suffering from severe knee swelling and spent several hours in hospital on Monday and Tuesday this week.
But medics have yet to determine the cause of the inflammation. The Chelsea striker will have further tests today - if the swelling has reduced enough for a scan.
Drogba's knee has caused him pain since the start of the season.
Chelsea's medical staff believed it may have been caused by a tiny piece of floating bone or cartilage rubbing against the muscle but there has been no precise diagnosis.