In June 2003 he left for Hellas Verona on loan with an option to buy him outright for €800,000,[2][3] Cassani was awarded the number 83 shirt.

[6] With Juventus facing the 2006 Italian football scandal they terminated all co-ownership deals, either selling or buying back, Verona bought Cassani outright in June 2006 for an undisclosed fee, thought to be around €1.43M.

On 6 April 2008, Cassani scored his first professional goal, a late 28 yard shot which gave Palermo a 3–2 home win against his former club Juventus ending a string of four consecutive defeats.

Cassani also served as team captain during the first period of the 2010–11 season due to the absence of both Fabrizio Miccoli and Fabio Liverani.

[17] In June 2013 Genoa did not excise their option to buy Cassani and sold Nenad Tomović to Fiorentina in a forced auction, as both clubs failed to form an agreement before the deadline.

[1] A quick, energetic and versatile right-footed full-back, although he is usually deployed on the right, Cassani is capable of playing along either flank, and is effective both offensively and defensively, due to his good defensive skills, consistency and work-rate, as well as his crossing accuracy, technique, and ability to make attacking runs; he has also occasionally been deployed as a centre-back, due to his tenacity and physique.