Oschersleben - Michael Schumacher's manager Sabine Kehm urged "restraint" on Wednesday as the record Formula One champion's 16-year-old son Mick began testing ahead of his car-race debut later this month.
While seven-time F1 champion Schumacher continues his recovery from injuries suffered in a ski accident in December 2013, son Mick began his first public test session before a large media presence in Oschersleben.
Mick Schumacher is set to make his car-racing debut in the ADAC Formula 4 series beginning on April 25-26 in Oschersleben in Lower-Saxony state.
But Kehm said the youngster would not be talking to the media, saying the priority was to gather experience on the track as he makes the step up from karting.
"We musn't forget that this is a young boy who has just turned 16," she said.
"From my point of view, and this is something I want to primarily ensure, we shouldn't raise expectations too high," she said.
"He will gain a lot of new experience this year and at the same time do everything to give his best. But of course I would like to ask very much for restraint so that he can really call on his best possible performance."
Schumacher, with his racing helmet on, climbed into his black-and-grey Van Amersfoort Racing car - a smaller and simpler version of a Formula One model - and spoke in detail with a team engineer.
After a long wait, he steered the car onto the track near Magdeburg ahead of the rest of the field to begin the session, which was closed off from the media.
After racing as Mick Junior last season when he finished runner-up in the German junior karting championship, Schumacher junior is now to drive under the Schumacher name in the Formula 4 series for junior drivers.
The eight-race series features a single car manufacturer (Tatuus) with a 160 horse-power engine capable of speeds up to 210 kilometres per hour.
His 45-year-old father is continuing his recovery at his home in Switzerland after being severely injured in a skiing accident at Meribel in France in December 2013.
He spent months in an induced coma until it was announced in June that he had regained consciousness.
Schumacher has continued his rehabilitation at home since September and his family have made clear from the beginning that no details will be revealed about his condition.