On 19 December 2007, just over a year after his debut goal against Rende, De Silvestri scored again in the Coppa Italia, this time against Napoli. He dedicated his goal to his close friend and fellow Lazio fan Gabriele Sandri, who was shot dead by a policeman at a service area near Arezzo. Since making his debut, De Silvestri has continued to improve the technical and tactical aspects of his game under the guidance of manager Delio Rossi. However a number of disagreement between De Silvestri and his club arose, most notably regarding difficult talks regarding the extension to his contract with Lazio. He also endured a frustrating 2008–09 season playing deputy to new signing Stephan Lichtsteiner and started in only 13 league matches. Due to the contract wrangles and his failure to dislodge Lichtsteiner, led to him being put on sale during the 2009 summer transfer window.