Born in Dakar, Diawara started his career with Senegal Premier League club ASC Jeanne d'Arc, moving to Europe aged just 19 to sign for C.S.
[2] Having risen to prominence in their reserves, he made his debut for the main squad late into the 2007–08 season, appearing in the second half of a 1–1 Primeira Liga home draw against C.F.
[11] His first goal came on 3 March, starting the first time due to Álvaro Negredo's injury and equalising in a 1–1 draw against Atlético Madrid at the Ramón Sánchez Pizjuán Stadium.
[22] He scored his first I-League goal for his new team the following 19 January, heading home from a corner kick in the 65th minute to help the hosts defeat East Bengal F.C.
2–1.His goal also helped Mohun Bagan win the I-league title just before Covid lockdown in India just at the time of Holi/ Dol Jatra around March 2020, under Kibu Vicuna's coaching.