World number 13 Paula Creamer and seventh-ranked Suzann Pettersen were also involved in the six-car crash late on Sunday in Bangkok, where they were driving to the airport to catch a flight to Singapore for the $1.4 million tournament which starts on Thursday.
World number nine Miyazato, who won in Singapore in 2010, practised for about 15 minutes at the Sentosa Golf Club on Wednesday before pulling out with whiplash.
"I have pain in my neck and shoulder, so I'll sit this tournament out as a precaution," the Japanese said.
American Creamer strained a muscle in her neck and sustained whiplash, but participated in a photo shoot on Tuesday with fellow LPGA Tour players Pettersen, Angela Stanford and world number one Yani Tseng to promote the event.
"I've felt better, that's for sure," Creamer said. "Those things happen all the time and you can't control something like that.
"I had pretty bad whiplash from hitting the headrest but I took it easy and hope that I can tee it up on Thursday. ... It's pretty amazing, like I said, how we walked away, but things happen."
Norwegian Pettersen escaped the worst of the crash as her vehicle was at the end of the convoy and avoided smashing into the other vehicles, but she was still shaken by the incident.
"We're just lucky enough that we all got away with no major injury." Pettersen said.