Flo then tried his luck in Italy, joining newly promoted Serie A team Siena on a free transfer in 2003. Flo played for Siena for two seasons, becoming a success in Italian football and helping the club establish themselves in the top division for the first time. He showed surprising versatility when he was asked by manager Giuseppe Papadopulo to play in a more withdrawn role as a second striker, behind Enrico Chiesa and Nicola Ventola, rather than in his usual role as a main striker. He excelled in this position and was ever-present for his club throughout the 2003–04 season, as he scored eight goals, helping Siena to avoid relegation: he scored his first goal for his new club against Empoli in the third round of the league on 20 September. The next goal came against Reggina in the sixth round 18 October. Later becoming matchwinner in a 1–0 home win against Udinese.