Mario Daniel Pierani Verstraete (born 25 July 1978) was an Argentine footballer. He had successful spells at San Luis de Quillota and Coquimbo Unido. Born in Rosario, Argentina, Pierani began his football career with local semi-professional sides Juventud Unida and Club Argentino. He continued to play for semi-professional clubs in Santa Fe Province, Argentina until 2009, when he moved to Chile. After seven years in Chile, including one season in the Primera A with San Luis, Pierani returned to Argentina. He scored the goal that qualified Sportivo Rivadiva for the final stage of the 2015–16 Copa Argentina.