| Argentina (2) |
|---|
| Del Potro, Juan Martin | | Mayer, Leonardo |
| | Belgium (2) |
|---|
| Bemelmans, Ruben | | Goffin, David |
| | Canada (2) |
|---|
| Pospisil, Vasek | | Shapovalov, Denis |
| | Croatia (2) |
|---|
| Cilic, Marin | | Coric, Borna |
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| France (3) |
|---|
| Benneteau, Julien | | Mannarino, Adrian | | Paire, Benoit |
| | Germany (3) |
|---|
| Gojowczyk, Peter | | Mayer, Florian | | Zverev, Mischa |
| | Hungary (1) |
|---|
| Fucsovics, Marton |
| |
| | Kazakhstan (1) |
|---|
| Kukushkin, Mikhail |
| | Netherlands (1) |
|---|
| Haase, Robin |
| |
| South Korea (1) |
|---|
| Chung, Hyeon |
| | Spain (2) |
|---|
| Bautista Agut, Roberto | | Verdasco, Fernando |
| | Swiss (3) |
|---|
| Chiudinelli, Marco | | Federer, Roger | | Laaksonen, Henri |
| | Ukraine (1) |
|---|
| Dolgopolov, Alexandr |
|
| United States (6) |
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| Donaldson, Jared | | Harrison, Ryan | | Johnson, Steve | | Sock, Jack | | Tiafoe, Frances | | Young, Donald |
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