Born in Rome, Farelli began his senior career at hometown Serie D club Astrea.
Siena
In mid-2002 he was signed by Siena. At that time Siena was a Serie B club. In 2003, he followed the team to promote to Serie A. In mid-2004 he left for Serie C2 club Nocerina,[1] but in January 2005 returned to the city of Siena.
Farelli returned to Italian fourth level in 2005–06 season, for Vittoria. Then he left for Serie C1 club Ancona[2] and then Lanciano. In February 2007 he received a call-up to Italy Universiade team for a training match.[3] In that match he was a substitute.[4]
Crotone
Farelli settled in Crotone in 2008–09 season, the first club that he spent more than 1 season. The team won the first ever promotion playoffs to the third level since 2008, the year that the level was renamed to Lega Pro Prima Divisione. He was the backup keeper of Emanuele Concetti in his two-year stay.
Siena (second spell)
In 2010–11 Serie B, Crotone signed Vid Belec and Giacomo Bindi, and Farelli was allowed to leave for Siena in 1+1 year deal.[5] Siena was newly relegated from Serie A at that time.
^ Written at Trapani. "Calcio, Trapani: presi Farelli, Guerrieri e Crecco" [Football, Trapani: signing Farelli, Guerrieri & Crecco]. Sport - 24 ore. La Repubblica (in Italian). Rome: Gruppo Editoriale L'Espresso. July 2016 [circa]. ISSN2499-0817. Retrieved 18 September 2018.