Alesi initially signed a contract with Williams for the 1991 season. However, he then opted instead to sign for Ferrari as the second driver alongside fellow countryman Alain Prost, and the Ferrari team had to pay Williams a fine of four million dollars. The move to Ferrari initially appeared to be a logical choice from a results perspective too, for Alain Prost had mounted a serious world championship challenge at Ferrari the previous year, and the 1991 Ferrari set good lap times in winter testing.