Jack Draper has revealed how his coach has hit him with a ban after reaching the US Open quarter-final. The Briton has quickly endeared himself to the Flushing Meadows crowd and will face Tomas Machac in his first Grand Slam quarter-final. The 22-year-old will face off against the world No. 39 on Monday, having beaten Botic van de Zandschulp in the third round at the Grandstand on Saturday. And the British No. 1 has admitted that he has been told to cut caffeine out of his diet, heading straight back to his Manhattan hotel every night rather than see the sights of New York. “My coach doesn’t w…