Kyrgios pulls out of US Open tune-up event with knee pain

Australian Nick Kyrgios pulled out of his first-round match with Britain's Andy Murray at the Winston-Salem Open on Sunday due to knee pain but the 26-year-old is confident he will be fit for next week's US Open Grand Slam.

Kyrgios withdrew from the ATP 250 event in North Carolina in a last-minute call, with lucky loser Noah Rubin replacing him. American Rubin lost 6-2 6-0 to former world number one Murray. World number 85 Kyrgios, who skipped the Tokyo Olympics because he did not want to play in front of empty stands, said he had been dealing with pain in his left knee in the last couple of weeks.