 He did not take part in another F1 race for five years, though he continued to test for Williams, and was active in sports car racing.In 1988, Williams called upon Schlesser to deputise for an unwell Nigel Mansell at the Italian Grand Prix at Monza.With 26 of the 31 cars allowed to start, Schlesser qualified 22nd, and thus made his Grand Prix début the day before his 40th birthday.