The main round of Qatar ExxonMobil Open, organized by the Qatar Tennis, Squash and Badminton Federation, kicked off today at Khalifa International Complex, with the participation of a large number of the world's top ranked players. The organizing committee said the top four players: Austrian Dominic Thiem, Swiss Roger Federer, Russian Andrei Rublev and Canadian Denis Shapopalov will not compete in the first main round, which will be held over two days, and that they will start their career from the second round,