On 26 August 2009, ACF Fiorentina signed the right-back from S.S. Lazio on a five-year deal, he was presented to the press in Florence on 27 August; on successive declarations, De Silvestri stated he had reluctantly decided to leave his favourite club due to his strained relationship with president Claudio Lotito.
On August 26, 2009, ACF Fiorentina signed right-back from S.S. Lazio on a five-year contract; he was introduced to the press in Florence on August 27th; De Silvestri later explained that his decision to leave S.S. Lazio was influenced by a strained relationship with president Claudio Lotito.