A right shoulder injury forced Simona Halep to quit the MIami Masters on Saturday, handing a third-round walkover win to Anastasija Sevastova.
Halep, seeded third, said her problem began to develop during early practice sessions and got worse this week as play began.
The Romanian won her opening match over Caroline Garcia on Thursday.
“I’m sorry I have to pull out of singles and doubles,” Halep said in a statement. “But my injury does not let me play here as expected.
“I’m sad that I can’t continue; I wanted to come here and give my best and play many matches but unfortunately I can’t.
“Hopefully next year I will be back healthy and better.”