Diego Manuel Jadon da Silva Moreira, a Belgian of Portuguese descent, was formed at Standard Liège and joined Benfica's academy in August 2020, entering at under-17 level.

A quick left-footed winger who could also operate as a left wing-back, he was central to the under-19 side that won the UEFA Youth League in 2021-22, the club's first, contributing goals and assists throughout the competition. He was promoted to Benfica B in January 2022 and made his senior debut on 13 May 2022, coming on for the final stages of a Primeira Liga match against Paços de Ferreira.

His second season was defined by a contractual impasse: having declined to sign new terms during pre-season, he was returned to the B team after one further senior appearance, a Champions League qualifier on 9 August 2022, and spent 2022-23 in the Liga Portugal 2 and with the under-20s. He finished with two official matches for the first team.

His contract expired and he left for Chelsea on a free transfer on 1 July 2023. A loan at Lyon followed before a permanent move to Strasbourg in August 2024.