US Open star Yulia Putintseva has issued a grovelling apology after being accused of ‘terrible behaviour’ towards a ball girl in her US Open defeat to Jasmine Paolini. The 29-year-old was booed by the crowd at the Louis Armstrong Stadium after appearing to snub a ballgirl. The youngster threw three balls in the direction of Putintseva. Yet the tennis star ignored the first two and stared back at the ball girl, sparking jeers around the ground, before catching the third and turning away. Boris Becker was unhappy with her antics and took to X to say: “Who does Putintseva think she is… “Terrible …