The Spaniard was due to visit the Kingdom this week for a beach holiday ahead of the $608,500 tournament in Bangkok. He will stay in Spain to receive treatment for what his doctor said is an acute rupture of an abdominal muscle.
Nadal admitted that the injury contributed to his US Open semi-final defeat by Argentine Juan Martin del Potro on September 13. He is expected to be sidelined for two to three weeks.
Frenchman Jo-Wilfried Tsonga, the defending champion, will be top seed for the Bangkok event.