MLS
USA
| Referee | Games |  |  | Cards per game |
|---|
| Rodrigo Albuquerque | 1 | 8 | 1 | 9.0 (8.0 / 1.0) | |
| Elijio Arreguin | 5 | 23 | 1 | 4.8 (4.6 / 0.2) | |
| Malik Badawi | 6 | 31 | 0 | 5.2 (5.2 / 0.0) | |
| Fotis Bazakos | 8 | 40 | 1 | 5.1 (5.0 / 0.1) | |
| Nabil Bensalah | 2 | 6 | 0 | 3.0 (3.0 / 0.0) | |
| Serhiy Boiko | 7 | 25 | 1 | 3.7 (3.6 / 0.1) | |
| Allen Chapman | 11 | 37 | 2 | 3.6 (3.4 / 0.2) | |
| Alexis Da Silva | 9 | 48 | 1 | 5.4 (5.3 / 0.1) | |
| Marcos de Oliveira | 6 | 20 | 0 | 3.3 (3.3 / 0.0) | |
| Sergii Demianchuk | 5 | 20 | 0 | 4.0 (4.0 / 0.0) | |
| Marcos DeOliveira II | 1 | 3 | 0 | 3.0 (3.0 / 0.0) | |
| Joe Dickerson | 7 | 30 | 2 | 4.6 (4.3 / 0.3) | |
| Filip Dujic | 8 | 31 | 2 | 4.2 (3.9 / 0.3) | |
| Ismail Elfath | 9 | 36 | 2 | 4.2 (4.0 / 0.2) | |
| Joshua Encarnación | 2 | 10 | 1 | 5.5 (5.0 / 0.5) | |
| Ricardo Fierro | 4 | 17 | 1 | 4.6 (4.3 / 0.3) | |
| Drew Fischer | 10 | 48 | 1 | 4.9 (4.8 / 0.1) | |
| Timothy Ford | 7 | 28 | 2 | 4.3 (4.0 / 0.3) | |
| Jon Freemon | 9 | 44 | 3 | 5.2 (4.9 / 0.3) | |
| Guido Gonzales Jr. | 5 | 23 | 2 | 5.0 (4.6 / 0.4) | |
| Jorge Gonzalez | 1 | 3 | 0 | 3.0 (3.0 / 0.0) | |
| Lorenzo Hernandez | 6 | 25 | 1 | 4.4 (4.2 / 0.2) | |
| Pierre-Luc Lauziere | 8 | 35 | 0 | 4.4 (4.4 / 0.0) | |
| Jair Marrufo | 6 | 12 | 1 | 2.2 (2.0 / 0.2) | |
| Rosendo Mendoza | 9 | 29 | 2 | 3.4 (3.2 / 0.2) | |
| Ricardo Montero | 6 | 31 | 3 | 5.7 (5.2 / 0.5) | |
| Chris Penso | 7 | 33 | 1 | 4.8 (4.7 / 0.1) | |
| Tori Penso | 7 | 29 | 0 | 4.1 (4.1 / 0.0) | |
| Victor Rivas | 10 | 52 | 3 | 5.5 (5.2 / 0.3) | |
| Brandon Stevis | 2 | 5 | 0 | 2.5 (2.5 / 0.0) | |
| Ramy Touchan | 2 | 15 | 1 | 8.0 (7.5 / 0.5) | |
| Rubiel Vazquez | 10 | 40 | 4 | 4.4 (4.0 / 0.4) | |
| Michael Venne | 1 | 4 | 0 | 4.0 (4.0 / 0.0) | |
| Armando Villareal | 6 | 25 | 0 | 4.2 (4.2 / 0.0) | |
England