History's most successful formula one driver, who hung up his helmet at the end of 2006, has been dabbling on motorcycles recently, including amateur races in Hungary and Spain.
Media reports said Schumacher actually won a 14-lapper at the Circuit de Catalunya over the Easter weekend, but the 39-year-old played down the triumph.
"I finished in front but they were young boys. This instead will be a real race, the first official one I've done on a bike," he told Italy's La Gazzetta dello Sport daily.
He refers to his planned 990cc KTM race at the Misano circuit this Sunday.
Schumacher said he hopes simply to qualify for the 10 lap race, among highly competitive semi-professional riders.
"This is just for enjoyment, no one is obliging me to do it. Maybe I will stop here," the German said.