The defensive midfielder moves to The City Ground on a season-long loan deal.
Cafu started out in the youth ranks of Benfica, going on to sign for Vitoria Guimaraes where he played in the Europa League. The 27-year-old then moved to France with Lorient and Metz, before signing for Legia Warsaw and helping them to the Polish league title in 2017-18, as well as scoring the winning goal in the Polish Cup final.
He joined Olympiacos halfway through last season, going on to help them to their league title success, as well as playing his part in the Greek Cup victory.
With 13 appearances in the Europa League and Champions League to his name, and 27 caps for Portugal at youth level, Cafu now joins up with The Reds for the 2020-21 campaign.