"I had a test and there were problems in my leg. It is impossible to drive properly at the moment," the Ferrari driver said.
It was Schumacher's first driving appearance since he broke his leg at the British Grand Prix on 11 July. But he had bad news for the many well- wishers present at Monza to cheer his return. "I don't think I will compete in the next two races," he said.
Thousands of fans gave the German an ovation when he returned to the pits after his first lap. Messages on banners in the stands read: "Welcome back, Michael", "Schumi, you are magic" and "The king is back".
His Ferrari team-mate, Eddie Irvine, and stand-in, Mika Salo, were also putting in a few laps, watched by their team manager, Jean Todt.
The Ulsterman currently trails the reigning world champion, Mika Hakkinen, by a single point in the drivers' championship, with Schumacher 28 points adrift in fifth.Reuse content