Izzo started playing football at the age of 13 with ARCI Scampia, before moving Napoli, where he also won a Campionato Nazionale Dante Berretti.
In the 2011–12 season he went on loan to Triestina in Lega Pro Prima Divisione, with whom he played 13 games and scored his first professional career goal.
[citation needed] On 1 September 2022, Izzo joined newly-promoted Serie A side Monza on a one-year loan.
[8] On 15 March 2019, Izzo received a call up from Roberto Mancini for Italy's UEFA Euro 2020 qualifying matches against Finland and Liechtenstein later that month.
[10] On 23 May 2016, Izzo, along with midfielders Luca Pini and Francesco Millesi, was put under investigation by the anti-mafia police department in Naples (DDA) after being accused of being directly involved with a Camorra clan based in Secondigliano in altering the results of the Serie B matches Modena–Avellino (1–0) from 17 March 2014, and Avellino–Reggina (3–0) from 25 May 2014.
On 3 March 2017, the Italian Football Federation's prosecutor asked for Izzo to be suspended for six years, also requesting that collateral estoppel be applied, and demanded that he should receive a €20,000 fine.