British number three Kyle Edmund has withdrawn from the US Open. The 26-year-old is still not fit after undergoing surgery on a persistent knee problem in March. Edmund, an Australian Open semi-finalist in 2018, has not played a competitive match since losing in the first round of qualifying in Vienna last October. He has subsequently slipped down the rankings from a career high of 14 and is currently outside the world’s top 100, at 102.The American Denis Kudla has replaced Edmund in the main draw at Flushing Meadows, the United States Tennis Association announced. The US Open begins on Monday 28 August with Britain’s Dan Evans, Cameron Norrie and the former champion Andy Murray in the men’s field. Meanwhile Johanna Konta was beaten in the first round of the -Western & Southern Open by the Australian Open semi‑finalist -Karolina Muchova despite winning the first set. Konta lost 3-6, 7-6 (5), 6-2 in 2hr 27min to end her seven‑match winning run, which comprised her Nottingham title in June and third‑round run in Montreal last week, where she withdrew before her third round match with a knee injury. Muchova, who endured a shock first-round defeat in Montreal against Oceane Dodin, also reached the -second round in Cincinnati on her debut last year. The three-times Western & -Southern Open runner-up Simona Halep overcame injury, rain and an intermittently impressive Magda Linette to seal her first win since May 6-4, 3-6, 6-0 in 2hr 10min. The No 12 seed had been out for three months with a calf injury.