| Yellow | Clubs | VS Club | Date | |
|---|---|---|---|---|
| 6 | FC Dallas | Sporting Kansas City | 15-08-2021 | Match details |
| 6 | Cincinnati | Columbus Crew | 10-07-2021 | Match details |
| 6 | Inter Miami CF | Chicago Fire | 22-05-2021 | Match details |
| 6 | Los Angeles Galaxy | Los Angeles FC | 09-05-2021 | Match details |
| 5 | Inter Miami CF | Atlanta United | 28-10-2021 | Match details |
| 5 | New York City | New England Revolution | 29-08-2021 | Match details |
| 5 | New York Red Bulls | Montreal Impact | 15-08-2021 | Match details |
| 5 | Real Salt Lake | Portland Timbers | 08-08-2021 | Match details |
| 5 | Sporting Kansas City | Los Angeles FC | 05-08-2021 | Match details |
| 5 | Los Angeles FC | Sporting Kansas City | 05-08-2021 | Match details |
