 Prósperi began his professional playing career with Godoy Cruz in 2005, after making 16 appearances for the club he was signed by Argentinos Juniors in 2006.He played on a fairly regular basis between 2006 and 2009 and in 2009 he became a near permanent fixture in the first team squad after the appointment of Claudio Borghi as manager.Prósperi was an important member of the Argentinos Juniors team that won the Clausura 2010 championship.