Career
He made his Serie A debut on 14 September 2002 against Empoli F.C. He also played over 200 games at Serie B. Allegretti was the captain of Triestina. In July 2009, he was signed by Associate of Science Bari along with team-mate Filippo Antonelli.
In 2010 he left for Serie B club United States. Grosseto F.C. On 31 August 2011 Grosseto announced that he was transferred to United States. Triestina Calcio. The club was newly relegated to 2011-2012 Lega Pro Prima Divisione.
Triestina bankrupted and folded at the end of season, thus Allegretti became a free agent
On 30 November 2012 Allegretti was signed by another third division club Barletta.
He made his debut in the following match day (2 December). He extended his contract on 12 July 2013.