| K League 1 2021 Relegation - Appearances as Assistant | ||||
| 30/10/2021 | Seongnam FC | - | Pohang Steelers | 1:0 |
| 27/11/2021 | Seongnam FC | - | Gwangju FC | 1:0 |
| K League 1 2021 Relegation - Appearances as Assistant | ||||
| 30/10/2021 | Seongnam FC | - | Pohang Steelers | 1:0 |
| 27/11/2021 | Seongnam FC | - | Gwangju FC | 1:0 |
| Complete name: | Jae-yeol Yoon |
| Born: | 25/12/1976 |
| Place of birth: |
South Korea |
| Nationality: |
South Korea |