A Ferrari spokesman said the retired 38-year-old German was merely following the progress of the team on the final day of pre-season testing in Europe at Barcelona's Circuit de Catalunya.
Although the most successful driver in the history of Formula One attended the launch of the new Ferrari at the team's Fiorano track in January, he has not been to a test session since he quit in October.
Ferrari have said seven-times world champion Schumacher, who has access to test data on his home computer, will continue with the team in a role yet to be defined.
Briton David Coulthard was quickest in his Red Bull, putting in 112 laps while watched by the team's billionaire owner Dietrich Mateschitz.
BMW Sauber's Nick Heidfeld of Germany was second quickest with Brazilian Felipe Massa third for Ferrari ahead of double world champion Fernando Alonso in a McLaren.
Toro Rosso's new Ferrari-powered STR2 car also made its track debut, with Italian Vitantonio Liuzzi putting in 43 laps, after a low-key launch on Tuesday.
The next test is in Bahrain on February 22. The season starts in Australia on March 18.
Text: Reuters | Photograph: Cesar Rangel/AFP/Getty Images