The Tournament caters for both the WTA and APT series. That means that the ladies qualification rounds will start today and the Round 1 tournament will commence on Wednesday. The qualification rounds for men is also starting today and the Round 1 matches will also start Wednesday. There will be 12 qualifiers that will be included in the main draw.
The ATP Draw is not available yet and is to take place today at 12:00 Miami time 18:00 SA time. All that is known at present is that Djokovic and Nadal will not play in this tournament. The draw will obviously be based on the rankings - but even that is not clear since the rankings may be influenced by the Indian Wells tournament outcomes - this will only be available later today.