| Argentina (2) |
|---|
| Del Potro, Juan Martin | | Mayer, Leonardo |
| | Bulgaria (1) |
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| Dimitrov, Grigor |
| | Canada (1) |
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| Pospisil, Vasek |
| |
| | Cyprus (1) |
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| Baghdatis, Marcos |
| | | Georgia (1) |
|---|
| Basilashvili, Nikoloz |
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| Germany (3) |
|---|
| Gojowczyk, Peter | | Zverev, Alexander | | Zverev, Mischa |
| | Hungary (1) |
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| Fucsovics, Marton |
| | Italy (4) |
|---|
| Berrettini, Matteo | | Cecchinato, Marco | | Fognini, Fabio | | Seppi, Andreas |
| |
| | Russia (2) |
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| Khachanov, Karen | | Rublev, Andrey |
| | Serbia (2) |
|---|
| Krajinovic, Filip | | Lajovic, Dusan |
| | Spain (4) |
|---|
| Bautista Agut, Roberto | | Lopez, Feliciano | | Ramos-Vinolas, Albert | | Verdasco, Fernando |
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| | United Kingdom (1) |
|---|
| Edmund, Kyle |
| | United States (4) |
|---|
| Harrison, Ryan | | Querrey, Sam | | Sandgren, Tennys | | Sock, Jack |
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