Mendes finally made his debut in the Portuguese top division on 11 January 2020, playing 14 minutes in the 3–1 away victory over Vitória de Setúbal. On 16 September, he joined Spanish Segunda División side UD Almería on a season-long loan. The following 1 February, however, he signed with C.D. Nacional also on loan. In his second appearance for the latter, as a second-half substitute against S.C. Farense, he scored twice (but one in his own net) in a 2–3 home loss.
