Diakité has signed a contract with Slavia Prague that lasts until 2031. Diakité, who is from Ivory Coast, played for Daugavpils in Latvia prior to his move to Liberec. He stated that his year in Liberec aided his improvement and that he is very happy to join Slavia Prague. He also expressed gratitude for joining with Ange N'Guessan, who is like an older brother to him.

Midfielder Toumani Diakité, a 20-year-old from Ivory Coast, is transferring from Liberec to Slavia Prague in a joint deal that also includes French defender Ange N’Guessan. The total value for both players could reach up to 12 million euros, or approximately 290 million CZK. Viktoria Plzeň was also actively interested in N'Guessan but reportedly withdrew as the asking price increased. The deal was finalized despite a statement made a few weeks prior by Liberec's owner, Ondřej Kania, in the Insider podcast that he would no longer conduct business with Slavia. As part of the compensation, midfielder Alexandr Bužek and winger Vasil Kušej are expected to move from Slavia to Liberec. The transfer is being described as a confirmation that the established course of Liberec is highly effective. Diakité joined Liberec in September 2025, had a contract until June 2029, and has a current valuation on Transfermarkt of €3.00m.