 Complete the following phrase:  After being a member of the Empoli youth side since 1994, Di Natale started his professional career with the Empoli senior side in 1996, and remained with the club until 2004, aside from brief loan spells with Iperzola, Varese and Viareggio. During his time with Empoli, he helped the club to achieve Serie A promotion during the 200102 Serie B season, scoring 16 goals. His breakthrough came during the 