Tickets for the Dubai Duty Free Tennis Championships will go on sale on Monday. This year’s line-up includes defending champion and crowd favorite Roger Federer, men’s world number one Novak Djokovic and women’s world number one Serena Williams. Organisers say fans are in for a treat as the sport’s biggest names battle it out on court in the early rounds, which begins on the 15th February. The Box Office at the Dubai Duty Free Tennis Stadium – usually open from 9 AM - opens at 8 AM tomorrow, in anticipation of early morning crowds.