Marsili made one appearance for Roma in Serie A at the age of 17, playing 36 minutes against Udinese on April 10, 2005. He was signed by Cosenza Calcio 1914 on 25 August 2009 in co-ownership deal. In June 2010 Roma gave up the remain 50% registration rights to Cosenza for free.
In 2010, he was signed by Nocerina. In January 2012 he left for Andria.
In 2012, he was signed by Martina of Serie C2.
In 2013, he was signed by Serie D club Brindisi. In December 2013 he was signed by fellow Serie D club Matera.. In 2017, he was signed by Nocerina of Serie D.