Nelly Korda will not compete in the first major of the year after failing to recover from a blood clot.
The world No.2 was hospitalised earlier this month, and is not in the field for the Chevron Championship.
The deadline for players to confirm their entries passed on Tuesday.
Korda’s illness was discovered when she developed swelling in her arm after a routine workout, which led to the diagnosis.
Since then she has been resting at home, with no timescale for when she aims to be back out on the course.
“I am currently at home getting treatment to eliminated further risks,” the 23-year-old said at the time.
“I will communicate my status as and when there is more information.
“In the meantime, I want to thank everyone for their support and ask for privacy for all our family during this time.
“I hope to be back soon.”