Renault doctor Riccardo Ceccarelli on Thursday admitted Robert Kubica's will be a "long" road to recovery.
Speaking at the Barcelona test, he said the injured Pole is recovering well in an Italian hospital after his horror rally crash more than a month ago.
"Robert is getting better day by day," Ceccarelli is quoted as saying by the team's official website.
He confirmed that the 26-year-old's physiotherapy programme is underway and that Kubica can now move his right wrist as well as fingers.
Ceccarelli also confirmed that Kubica's mental state has been "up and down" but he is now pushing hard to return to full fitness.
But as for naming an estimated date for his return to action, the Italian doctor is cautious.
"Nobody has a clear idea of when he will be ready," he said.
"All we know that it will be a long recovery, but we have no idea how long. We see his progress day by day, but we can't make any predictions."