| Yellow | Clubs | VS Club | Date | Sections | |
|---|---|---|---|---|---|
| 6 | Shakhtar Donetsk | AS Monaco | 25-08-2021 | Play Off Round | Match details |
| 6 | Ferencvaros | BSC Young Boys | 24-08-2021 | Play Off Round | Match details |
| 5 | Benfica | PSV Eindhoven | 24-08-2021 | Play Off Round | Match details |
| 5 | Benfica | PSV Eindhoven | 18-08-2021 | Play Off Round | Match details |
| 5 | Red Star Belgrade | FC Sheriff Tiraspol | 03-08-2021 | Third round | Match details |
| 4 | AS Monaco | Shakhtar Donetsk | 25-08-2021 | Play Off Round | Match details |
| 4 | FC Sheriff Tiraspol | Red Star Belgrade | 03-08-2021 | Third round | Match details |
| 3 | FC Sheriff Tiraspol | Dinamo Zagreb | 25-08-2021 | Play Off Round | Match details |
| 3 | Ludogorets Razgrad | Malmo FF | 24-08-2021 | Play Off Round | Match details |
| 3 | PSV Eindhoven | Benfica | 24-08-2021 | Play Off Round | Match details |
