Michael Schumacher's manager Sabine Kehm hopes the seven-time world champion "is back with us" one day, admitting the recovery process requires a lot of patience.
Schumacher suffered serious head injuries in a skiing accident at the end of 2013 and left hospital nearly a year later to continue his recovery at home.
Although there has never been a detailed update on his condition, Kehm suggested there is still a long way to go for the 47-year-old.
"He is the most successful driver in history and sometimes, on days like this, it is good to be reminded of it," Kehm was quoted as saying by the BBC during the opening of an exhibition celebrating Schumacher's career.
"Of course, Michael is not here and of course we miss him. We know what has happened and cannot change it.
"We must accept it and hope with everything we have that, with continued support and patience, he will one day be back with us," she added.