Career
Di Masi started his career at hometown club Foggia where he became the first choice in 1999-2000 Serie C2 season, after Foggia relegated from Serie C1. Roma
In 2000, he was signed for Roma along with team-mate Attilio Nicodemo and Franco Brienza. Di Masi signed a 5-year contract and cost Roma 50 million lire (€25,823).
He played half season at Roma"s Primavera U20 youth team as one of the keeper along with Matteo Napoli and Simone Paoletti.
Then in January 2000 joined Roma"s sister club Palermo (from March 2000 until July 2002) on loan, re-united with Nicodemo. He played as one of the Vincenzo Sicignano"s backup.
Reggiana
In July 2001, he joined Reggiana in co-ownership deal, as part of Adewale Wahab"s deal to Roma. (50% registration rights of Di Masi tagged for 2,500 million lire.
Around €1,291,142, while Wahab tagged for 3,000 million lire.
€1,549,371) From November to February he was the first choice ahead Patrick Bettoni, then Bettoni restored as first choice. In the 2002-2003 season, he was the backup of Raffaele Nuzzo and Luca Mondini. In January 2003, he left for Serie C1 side Pisa.
Lega Pro
In June 2003, Reggiana got the remain 50% registration rights from Roma for free, but sent him to Acireale of Serie C1.
He then played as first choice for Serie C1 club Sangiovannese, then Serie C2/Lega Pro Seconda Divisione side Igea Virtus and Barletta. In 2010-2011 Lega Pro Prima Divisione season, the division newcomer signed Andrea Tesoniero as first choice and Renato Dossena as backup keeper, made Di Masi became the third keeper.
Since October he became the first choice again, due to the injury of Tesoniero. He also played twice in 2010-2011 Coppa Italia Lega Pro.
In January 2011 the team signed the new keeper Ugo Gabrieli.
Di Masi was released on 30 June 2011. In October 2011 Di Masi joined Serie Doctorate club Marsala. In July 2012 Di Masi returned to professional football for Avellino, as the backup of Ermanno Fumagalli.