US Open: Novak Djokovic retires vs. Stan Wawrinka with shoulder injury. Stan Wawrinka has advanced to the US Open quarterfinals after defending champion Novak Djokovic retired in the third set of their match Sunday night. The 23rd-seeded Wawrinka was leading two sets to none when Djokovic had to stop because of a left shoulder injury, which he had been dealing with throughout the tournament. The two were facing each other for the first time since they met in the 2016 US Open final. After Wawrinka won the first two sets 6-4, 7-5 and was up 2-1 in the third, fans at the US Tennis Center expressed their displeasure when Djokovic informed the umpire he was unable to continue the match. “It’s never the way you want to finish a match, Wawrinka said in his post-match interview with ESPN. “I’m really sorry for Novak. He’s a good friend, he’s an amazing champion. We’ve played some amazing battles my whole career, so I feel sorry for him. But I was playing some very good tennis. I’m happy to be back.
