Despite the world number nine's withdrawal, a strong field is expected for the event, including Roger Federer, Kei Nishikori, Milos Raonic, Grigor Dimitrov and Juan Martin del Potro, who have all confirmed their participation.
On the men's side, the fields have already been divided into two ATP 250 tournaments.
Former world number one Andy Murray withdrew from the Brisbane International with a hip problem on Tuesday, further putting in doubt the Briton's prospects of being fit in time for the Australian Open later this month.