Charley Hull will miss this week's ANA Inspiration tournament in California, the second women's Major event of the rescheduled season, after testing positive for Covid-19.
England's top player finished tied for 22nd place at the Women's Open in Scotland last month.
"I didn't feel great [on Monday] but I put it down to jet lag, the heat and my asthma playing up," Hull said. "I now realise I have some mild symptoms which feel similar to having a cold.
"I am very disappointed to have to withdraw from what is one of my favourite events of the year."