Washington - Britain's Andy Murray and Japan's Kei Nishikori will stop at the ATP event in Washington in their August preparations for this year's US Open, tournament officials have announced on Thursday.
World number four Murray, the 2012 US Open and Olympic champion and 2013 Wimbledon winner, has not played in the hardcourt event at the US capital since 2006, when he lost to Frenchman Arnaud Clement in the final.
Fifth-ranked Nishikori, who lost to Croatian Marin Cilic in last year's US Open final in his first Grand Slam championship match, made Washington's Citi Open his only hardcourt stop ahead of his Flushing Meadows run, falling to France's Richard Gasquet in the quarter-finals.
"Andy and Kei are two of the most dynamic and popular players in the world and we're happy to have them make such an early commitment," ATP Citi Open tournament director Jeff Newman said. "It sends an early message that DC is a top tournament to play."
The August 3-9 tournament will be staged one week before the ATP Masters Series event in Montreal and two weeks before the Cincinnati Masters, both of which figure to lure all of the world's top players as the main tuneups for the year's final Grand Slam event, which begins August 31 at New York.
"If you are Andy Murray and you are going to try to win the US Open, you want to get here early and get sharp. This helps with that in every way," tournament chairman Donald Dell said.
Argentina's Juan Martin del Potro is the last player to win the Washington crown on the way to capturing the US Open title, doing so in 2009 before shocking Roger Federer in a thrilling five-set final of Flushing Meadows.
World number six Milos Raonic is the reigning champion at the $1.5 million (1.4 million euro) event, having beaten Vasek Pospisil 6-1, 6-4 last in the ATP's first all-Canadian singles final.
Washington was Raonic's first stop after a career-best Grand Slam run to the Wimbledon semi-finals last year.
Murray, 27, has won 31 career ATP singles crowns, three of them coming last year in Shenzen, Vienna and Valencia.
Nishikori, 25, won his eighth career ATP crown earlier this year at Memphis, his third consecutive trophy at the event.
Their early move could boost the field in Washington, which also stages a WTA event the same week. It comes one week after the opening US hardcourt event of the US Open run-up in Atlanta.
"This will help us certainly in attracting three or four more top 12 players in the world," Dell said. "We hope to have five of the top 10 players in the world."