In contact with basketball since he was a child, Giovanni took his first steps at Vigodarzere Basketball, the club founded by his father Stefano, with whom he played the Regional Serie C Championship, when he was not even 18. After his time in Serie D in Mestrino and in C2 in Limena, he wore a Vicenza Basketball jersey, the team with whom he won the C1 championship, and then in 2015-2016, he moved on to Casale, where he put his skills to the test in the A2 championship. The following season he went to America where he studied and played at the University of Texas at San Antonio. Wearing a Roadrunner jersey, Giovanni managed to not only lay down some good stats but also, more importantly, exhibited his leadership skills, becoming one of the best youngsters in the club’s history. Following his training experience in the USA, De Nicolao returned to Italy and accepted Agrigento’s offer. He had an excellent year with the Sicilians (9.6 points, 3.9 rebounds and 3.6 assists per game) during which he confirmed himself as a quality player.