Agomeri Antonelli started his career at Monza, at that time Serie C1, after played one Serie B game for the club, he transferred to L'Aquila of Serie C2 Group C. He then moved to Pro Patria, in Serie C2 Group A.
He was signed by Cosenza in summer 2001, started his full Serie B season.
He was signed by Ascoli of Serie B in summer 2003. He won the Serie A promotion in summer 2005.
Due to good performance in Ascoli, Chievo signed him in summer 2005, his first Serie A club. After made only one appearance, he was loaned to Messina in winter break, to help the club avoid relegation.
In summer 2006, he was loaned to Pescara Calcio. Team-mate Stefano Olivieri also joined the club in co-ownership deal.
In July 2007, half of the registration rights was sold to Triestina for €110,000 in 2-year contract.
In January 2008, he plays for U.C. AlbinoLeffe, on loan. He was full contracted with Triestina in June 2008 for free.
On 20 July 2009, Bari have signed the former Triestina right winger on a free transfer and until June 2011. In January 2010 he left for Torino in temporary deal, with Marco Pisano moved to Bari also in temporary deal.
In August 2010, he returned to his former club Triestina for free, but after a good season with 33 caps and 1 goal, the club relegated in Lega Pro, his contract expired and he becomes a free agent.
After the bankruptcy of Triestina, Antonelli joined Lumezzane in August 2011. In August 2012 he joined Reggiana, with Riccardo Carlini moved to opposite direction. Antonelli signed a 2-year contract.