Cássio Santiago de Almeida joined Odra Opole from Pogoń Siedlce. The 25-year-old center-back signed a contract with his new team until the end of the 2026/2027 season, with an option for an additional year. In the previous season, he was the player with the most minutes on the field for his team in the Mazovian Voivodeship, making 26 appearances and recording an assist against Miedź Legnica.

Cassio, currently with Pogoń Siedlce, is attracting interest from Odra Opole. The transfer of his compatriot Rodrigo to Pogoń Siedlce is dependent on Cassio's departure. Both players are represented by the same agency, which might facilitate the transfer. Transfermarkt currently estimates his market worth at 150k euros.