Vu issued a statement on Instagram saying she had "severe discomfort" in her back during warm-ups on Thursday which had forced her withdrawal.
"I have been dealing with a back injury for a while now," she said in the statement.Â
"Some days are better than others, and today was unfortunately not a good day. During my normal warm-up routine, I had severe discomfort in my back and I felt that I could not compete up to my standards and made the decision to withdraw from the tournament ahead of my tee time."
She added that she was returning home immediately to see her doctors and determine the next steps.
The back issue has already forced Vu to withdraw from a previous event this season.
The 26-year-old American was asked about her health leading up to the tournament on Tuesday.
"It's been a rough couple months battling with my injury," she said. "It's been a little scary. I've definitely cried a lot on the range sometimes because my back just couldn't hold up."
She added that she felt "95 per cent there."
American Vu was the LPGA player of the year last season, having also won the Women's British Open after her Chevron victory.
12°C