Additions
| from | Name | Pos | Team | Team | ||
|---|---|---|---|---|---|---|
| 11/2021 |  | Won-jin Jung | MF |  | Gimcheon Sangmu | Gimcheon Sangmu |
| 11/2021 | | Dong-jin Park | MF | | Gimcheon Sangmu | Gimcheon Sangmu |
| 09/2021 | | Ik-soo Ahn | MA |  | Sunmoon University | Sunmoon University |
| 07/2021 | | Reum Yeo | MF |  | Jeju SK FC | Jeju SK FC |
| 07/2021 |  | Connor Chapman | MF | |||
| 07/2021 | | Dong-won Ji | FW |  | 1. FSV Mainz 05 | Mainz 05 |
| 06/2021 |  | Gabriel Barbosa | FW |  | Paysandu - PA | Paysandu SC |
| 02/2021 | | Seong-jin Kang | FW |  | FC Seoul U18 | U18 |
| 02/2021 | | Joon-ho Hong | DF | |||
| 01/2021 |  | Aleksandar Paločević | MF |  | CD Nacional | CD Nacional |
| 01/2021 | | Sang-ho Na | FW |  | FC Tokyo | FC Tokyo |
| 01/2021 | | Gi-hun Ahn | FW | |||
| 01/2021 | | Han-beom Lee | DF | |||
| 01/2021 | | Tae-seok Lee | DF | | FC Seoul U18 | U18 |
| 01/2021 | | Won-seong Sim | DF |  | Ajou University | Ajou University |
| 01/2021 | | Hak-seon Lee | MF |  | Pocheon FC | Pocheon |
| 01/2021 | | Sang-hoon Paik | MF | | FC Seoul U18 | U18 |
| 01/2021 | | Jae-won Shin | MF |  | Ansan Greeners | Ansan Greeners |
| 01/2021 | | Ho-jun Son | MF | |||
| 01/2021 | | Min-gyu Oh | FW | |||
| 01/2021 | | Jung-bin Park | FW | |||
| 01/2021 | | Jin-sub Park | MA |  | Gwangju FC | Gwangju FC |
Departures
| from | Name | Pos | Team | Team | ||
|---|---|---|---|---|---|---|
| 07/2021 | | Joon-ho Hong | DF | | Jeju SK FC | Jeju SK FC |
| 07/2021 | | Jin-wook Jung | GK |  | Gimhae FC | Gimhae FC |
| 03/2021 |  | Ikromzhon Alibaev | MF |  | Daejeon Hana Citizen | Daejeon |
| 03/2021 | | Adriano | FW |  | Jacuipense - BA | Jacuipense |
| 03/2021 | | Ju-sung Kim | DF | | Gimcheon Sangmu | Gimcheon Sangmu |
| 03/2021 | | Hyeon-cheol Jeong | MF | | Gimcheon Sangmu | Gimcheon Sangmu |
| 03/2021 | | Hak-seon Lee | MF | | Pocheon FC | Pocheon |
| 02/2021 | | Seung-jae Lee | FW |  | Chungnam Asan FC | Chungnam Asan |
| 01/2021 | | Ju-tae Yun | MF |  | Gyeongnam FC | Gyeongnam FC |
| 01/2021 | | Se-jong Ju | MF |  | Gamba Osaka | Gamba |
| 01/2021 | | Young-sun Yun | DF |  | Ulsan HD FC | Ulsan HD FC |
| 01/2021 | | Seung-gyu Han | MF |  | Jeonbuk FC | Jeonbuk |