Complex sentence: The 2006 Tour had been plagued by the Operación Puerto doping case before it began, favourites such as Jan Ullrich and Ivan Basso were banned by their teams a day before the start.
Split into simpler sentences: The 2006 Tour had been plagued by the Operación Puerto doping case before it began. Favourites such as Jan Ullrich and Ivan Basso were banned by their teams a day before the start.