Cassius was promoted to Lusa's main squad in 2013 by manager Péricles Chamusca, aged only 17. However, he failed to make a single appearance during the year, as his side suffered relegation from Série A.
In 2014, Cassius suffered a severe knee injury which kept him sidelined for one year. After again being not used, he left the club and joined Santos, in a one-year loan deal on 14 January 2016.[3]
Cassius left Santos in the end of the year, without playing a single minute for either the first team or the B-side. In May 2017 he joined URT, and made his senior debut on 21 May by coming on as a second-half substitute for Allan Dias in a 3–0 Série D away loss against Portuguesa-RJ.
^"Darla, Cassius e Gualberto já são Raposa" [Darla, Cassius and Gualberto are already of Raposa] (in Portuguese). Grêmio Anápolis. 15 December 2017. Retrieved 14 January 2018.