Career
In his playing career he played for Olympique Marseille and France at Euro 1992. Managerial career = Évian In January 2010, Casoni was named manager of Évian Thonon Gaillard Football Club whom he guided two successive promotions. He voluntarily resigned from his position on 2 January 2012 in the winter break of the season.
= Auxerre On 17 March 2014 Casoni was sacked as coach of Auxerre with the club just one point above the second tier"s relegation zone.
= Videoton On 10 June 2015, Casoni was appointed as the coach of the Hungarian League club Videoton Football Club of Székesfehérvár. On 19 August 2015, Casoni was sacked from Videoton after 4 defeats in 5 Nemzeti Bajnokság I matches in the 2015-2016 season and after 1 victory and 2 draws and 1 defeat in the 2015-2016 Union of European Football Associations Champions League.
Casoni"s early farewell was hugely affected by the resignation of the club director of Videoton, Győző Burcsa. In an interview with the Hungarian sport magazine, Nemzeti Sport, Casoni said that he was deceived by Videoton since the club let their key players (Nikolić, Calatayud, and Sándor) to be signed by other clubs and no new quality players were signed instead of them.
In the interview, he also said that players like Gyurcsó and Kovács are of mediocre quality.
Player Manager Videoton Hungarian Super Cup Runner-up: 2015.