| K League 1 2021 - Appearances as Assistant | ||||
| 06/03/2021 | Jeju United | - | Jeonbuk FC | 1:1 |
| 04/08/2021 | Suwon FC | - | Jeonbuk FC | 1:0 |
| 10/09/2021 | Pohang Steelers | - | Daegu FC | 1:2 |
| 03/10/2021 | FC Seoul | - | Daegu FC | 1:1 |
| K League 1 2021 - Appearances as Assistant | ||||
| 06/03/2021 | Jeju United | - | Jeonbuk FC | 1:1 |
| 04/08/2021 | Suwon FC | - | Jeonbuk FC | 1:0 |
| 10/09/2021 | Pohang Steelers | - | Daegu FC | 1:2 |
| 03/10/2021 | FC Seoul | - | Daegu FC | 1:1 |
| Complete name: | Eun-seok Gu |
| Born: | |
| Place of birth: |
South Korea |
| Nationality: |
South Korea |