Returning to Cincinnati is one of the main warm-up tournaments for the US Open in the Western & Southern Open which will take place between August 14-22 with the Entry List on the men's side headlined by Alexander Zverev, Daniil Medvedev and Stefanos Tsitsipas.
Novak Djokovic and Roger Federer decided against playing the US Open warm-up as well as Rafael Nadal meaning like in Toronto there will be no so called Big Three.
Wildcards were announced also as of the last update with former champion, Andy Murray joining rising stars, Jenson Brooksby and Brandon Nakashima as well as Frances Tiafoe in the draw.
2021 ATP Western & Southern Open Entry List (Last Update - 11/08/2021 - Wildcards announced, Djokovic and Coric removed)
1 Novak Djokovic
2 Daniil Medvedev
3 Rafael Nadal
4 Stefanos Tsitsipas
5 Alexander Zverev
6 Dominic Thiem
7 Andrey Rublev
8 Matteo Berrettini
9 Roger Federer
10 Denis Shapovalov
11 Pablo Carreno Busta
12 Hubert Hurkacz
13 Diego Schwartzman
14 Casper Ruud
15 Felix Auger-Aliassime
16 Roberto Bautista Agut
Alex de Minaur
Gael Monfils
Cristian Garin
David Goffin
Grigor Dimitrov
Milos Raonic
Jannik Sinner
Aslan Karatsev
Karen Khachanov
Lorenzo Sonego
Daniel Evans
Ugo Humbert
Stan Wawrinka
Cameron Norrie
Fabio Fognini
Reilly Opelka
Borna Coric
Filip Krajinovic
Alejandro Davidovich Fokina
Marin Cilic
Taylor Fritz
Marton Fucsovics
John Isner
Alexander Bublik
Adrian Mannarino
Nikoloz Basilashvili
Albert Ramos-Vinolas
Kei Nishikori
Sebastian Korda
Jan-Lennard Struff
(WC) Andy Murray (GBR)
(WC) Jenson Brooksby (USA)
(WC) Brandon Nakashima (USA)
(WC) Frances Tiafoe (USA)
(SE)
(Q)
(Q)
(Q)
(Q)
(Q)
(Q)
(Q)