Former Champions Headline Men's Field

Former Western & Southern Open singles champions Andy Murray and Rafael Nadal highlight the men’s main draw, which was released during Friday night’s draw party at the Lindner Family Tennis Center.
Murray, the No. 1 seed and current world No. 2, was the tournament winner in Cincinnati in 2008 and 2011. Nadal, seeded third, won the Rookwood Trophy in 2013. Both players won matches today to advance to the singles semifinals of the Rio Olympics.
Stan Wawrinka, the Swiss No. 2 seed, was on hand for the draw party. He has reached the quarterfinals here the last two years and was a semifinalist in 2012, his best finish in Cincinnati. He has won one ATP Masters 1000 titles (Monte Carlo, 2014) in addition to his two Grand Slam titles. 
Milos Raonic of Canada rounds out the top seeds at No. 4. He enjoyed his breakout Grand Slam performance earlier this summer when he advanced to the finals of Wimbledon, losing to Murray in the title match. 
Kei Nishikori of Japan, seeded fifth, is in the tournament field for the first time since 2013. Like Murray and Nadal, he is also still making his bid for an Olympic gold after defeating Gael Monfils of France in the quarterfinals earlier today.  
Potential Quarterfinal Matchups: If the seeding holds, potential quarterfinal matchups include Murray against Nishikori, Raonic against Dominic Thiem (AUT), Tomas Berdych (CZE) against Nadal, and Jo-Wilfried Tsonga (FRA) against Wawrinka.
American Openers: Before qualifiers are entered into the draw, there are six Americans already in the main draw field: John Isner, Sam Querrey and Steve Johnson in addition to wild cards Taylor Fritz, Reilly Opelka and Jared Donaldson. 
In the first round, Isner faces Fabio Fognini of Italy, Querrey plays Pablo Cuevas of Uruguay, Johnson faces Federico Delbonis of Argentina, Opelka takes on Jeremy Chardy of France and Donaldson meets Nicolas Almagro of Spain. Fritz plays a qualifier. 
Johnson has enjoyed a strong summer and is currently ranked No. 22 in the world rankings. He made the round of 16 at Wimbledon and was also a semifinalist at the Citi Open in Washington, D.C. He made the quarterfinals of the Olympic Games this week. 
Let the Tournament Begin: Singles qualifying begins Saturday at 10 a.m. Eastern. The main draw starts Sunday night with featured matches at 7 p.m., and the main tournament begins in earnest Monday morning. 
US Open Series Winners: Two winners of the Emirates Airlines US Open Series will be on hand this week: Gael Monfils of France and Nick Kyrgios of Australia. Monfils, currently ranked No. 11 in the world, won his sixth career ATP title last month at the Citi Open in Washington, D.C. Kyrgios, ranked No. 16, won last week’s BB&T Atlanta Open.