He made his Biancoceleste debut in a Coppa Italia match against Inter and continued to establish himself as a regular, becoming a key player in a high-flying Lazio team.

Manager Delio Rossi began to use him as a trequartista, behind Goran Pandev and Tommaso Rocchi, and he continued to shine, being a protagonist in Lazio's qualification for the UEFA Champions League.

He came back to lead Lazio as captain in the Derby Della Capitale and scored the winning goal, celebrating under the Curva Nord.

[6] Following the expiration of his contract with Lazio in July 2016, Mauri became a free agent and remained without a club for the first half of the 2016–17 season.

On 11 January 2017, Mauri joined Serie B side Brescia; this was his second spell with the club and the first time he had played for the team since his loan deal ended in 2004.

On 28 May 2012, Mauri was arrested by Italian Police for his alleged involvement in the Calcioscommesse sports betting scandal.