World number one Jannik Sinner has pulled out of the Shanghai Masters (a top-tier men's tournament held in China, 7–18 October) because of a right knee injury that has kept him sidelined since he won Wimbledon in July; surgery within the next month has not been ruled out. His absence gives Germany's Alexander Zverev, this year's winner of Roland Garros and the US Open according to the source, a chance to finish the season ranked first for the first time if he wins both the ongoing China Open in Beijing and the Shanghai event, with Novak Djokovic awaiting him in the Beijing quarter-finals.