Globo.com reports that Gusttavo was loaned to Estoril at no cost.

The loan transfer of Gusttavo to Estoril is official, according to Record. Flamengo has loaned the player until the end of the season, and Estoril holds a purchase option of one million euros.

Gusttavo de Sousa Oliveira, a 20-year-old Brazilian right-back, has moved from Flamengo to Estoril on loan in a deal completed at the end of the summer transfer window. The Portuguese club has a purchase option valued at one million euros. The defender, who can also operate on the left wing, had previously only played for Flamengo, making two appearances for the senior team in 2026 for a total of 133 minutes in the Campeonato Carioca. In the 2025/2026 season, he also made 36 appearances for the U20 team in the CBF Brasileiro U20, scoring one goal, and provided one assist in four Copinha games. It is reported that Estoril considers him a significant future prospect, and he is expected to begin with the U-23 team there.