| Argentina (3) |
|---|
| Baez, Sebastian | | Cachin, Pedro | | Schwartzman, Diego |
| | Austria (3) |
|---|
| Ofner, Sebastian | | Rodionov, Jurij | | Thiem, Dominic |
| | France (3) |
|---|
| Assche, Luca Van | | Halys, Quentin | | Lestienne, Constant |
| | Italy (5) |
|---|
| Cecchinato, Marco | | Fognini, Fabio | | Giannessi, Alessandro | | Nardi, Luca | | Zeppieri, Giulio |
|
| | | Poland (1) |
|---|
| Hurkacz, Hubert |
| | Portugal (4) |
|---|
| Borges, Nuno | | Rocha, Henrique | | Sousa, Joao | | Sousa, Pedro |
|
| Serbia (1) |
|---|
| Kecmanovic, Miomir |
| | Spain (4) |
|---|
| Bautista Agut, Roberto | | Davidovich Fokina, Alejandro | | Ramos-Vinolas, Albert | | Zapata Miralles, Bernabe |
| | Taiwan (1) |
|---|
| Tseng, Chun-Hsin |
| | United States (1) |
|---|
| Shelton, Ben |
|