Additions
| from | Name | Pos | Team | Team | ||
|---|---|---|---|---|---|---|
| 02/2021 |  | Robin Himmelmann | GK | |||
| 01/2021 |  | Aleksandar Boljević | FW |  | Standard Liège | Standard Liège |
| 01/2021 |  | Rocky Bushiri | DF |  | KV Mechelen | Mechelen |
| 09/2020 |  | Edo Kayembe | MF |  | RSC Anderlecht | Anderlecht |
| 09/2020 |  | Emmanuel Agbadou | DF |  | US Monastir | USM |
| 08/2020 |  | Smail Prevljak | FW |  | RB Salzburg | RB Salzburg |
| 08/2020 |  | Víctor Vázquez | MF |  | Umm-Salal | Umm-Salal |
| 08/2020 |  | Adriano | DF |  | Athletico Paranaense | Athletico - PR |
| 08/2020 | | Mamadou Koné | FW |  | CD Leganés | Leganés |
| 08/2020 | | Julien Ngoy | FW |  | Stoke City U21 | Stoke City U21 |
| 07/2020 |  | Benoît Poulain | DF | |||
| 07/2020 | | Jonathan Heris | DF |  | Újpest FC | Újpest FC |
| 07/2020 | | Senna Miangue | DF | |||
| 07/2020 | | Stef Peeters | MF |  | Cercle Brugge | Cercle |
| 07/2020 | | Théo Defourny | GK |  | Sporting Lokeren | KSC Lokeren |
| 07/2020 | | Tom Roufosse | GK | |||
| 07/2020 | | Marciano Aziz | MF |  | KAS Eupen U19 | U19 |
| 07/2020 |  | Amara Baby | FW |  | Royal Antwerp FC | Antwerpen |
| 07/2020 |  | Ibrahim Diallo | G-AN |  | KAS Eupen II | KAS Eupen II |
Departures
| from | Name | Pos | Team | Team | ||
|---|---|---|---|---|---|---|
| 02/2021 |  | Menno Koch | DF |  | CSKA Sofia | CSKA Sofia |
| 02/2021 | | Ortwin De Wolf | GK | | Royal Antwerp FC | Antwerpen |
| 01/2021 |  | Carlos Embalo | FW |  | AD Alcorcón | Alcorcón |
| 01/2021 | | Nils Schouterden | MF |  | AEK Larnaca | AEK Larnaca |
| 09/2020 |  | Flavio Ciampichetti | FW |  | Cultural Leonesa | CD Leonesa |
| 08/2020 | | Romain Matthys | GK |  | RWDM Brussels | RWDM |
| 08/2020 | | Mégan Laurent | MF |  | Jeunesse Esch | Jeunesse Esch |
| 07/2020 | | Siebe Blondelle | DF |  | KMSK Deinze | SK Deinze |
| 07/2020 |  | Olivier Verdon | DF |  | CD Alavés | Alavés |
| 07/2020 |  | Saeid Ezatolahi | MF |  | FK Rostov | FK Rostov |
| 07/2020 | | Jonathan Bolingi | FW | | Royal Antwerp FC | Antwerpen |
| 07/2020 | | Jon Bautista | FW |  | Real Sociedad | Real Sociedad |
| 07/2020 | | Smail Prevljak | FW | | RB Salzburg | RB Salzburg |