Centre-backs
Joel Matip - The Cameroonian international joined the club as a 9-year-old and went on to become one of the most accomplished centre-backs in the Bundesliga during his prime days with the club.
Matip made 194 Bundesliga appearances for Gelsenkirchen spanning across seven years, before joining the Premier League side Liverpool on a free transfer in 2016.
Matip started his Liverpool career excellently and received a lot of plaudits during his first season at the club. But he suffered quite a few injury problems during his second season at the club hampering his consistency.
Benedikt Howedes - German international Benedikt Howedes joined his boyhood club at the age of 13 and graduated through S04's youth system to become the club captain in 2011.
The centre-back made more than 300 appearances for the Royal Blues and helped the team win DFB-Pokal in 2011 and DFL Supercup in 2011.
He joined Juventus on a season-long loan with an option to buy in 2017, but the Old Lady opted against making his move permanent and he joined Locomotive Moscow in the summer transfer window of 2018.
Howedes won the FIFA World Cup 2014 and holds 44 senior German caps to his name till date.