The 45-year-old Schumacher fell while skiing in France and hit the right side of his head on a rock, cracking his helmet.
Doctors operated to remove blood clots from his brain, but some were left because they were too deeply embedded.
Doctors have started the gradual process of waking him up from the induced coma.
His agent, Sabine Kehm, said in an email today that 'Michael is still in the wake-up phase' and that 'this phase can be long.'
Schumacher's family has released few details of his condition to protect his privacy.
'It does not bode well,' said Dr. Tipu Aziz, professor of neurosurgery at Oxford University who is not connected to Schumacher's care.
'The fact that he hasn't woken up implies that the injury has been extremely severe and that a full recovery is improbable.'