"They will all be monitored in the coming days.
"We want to thank the emergency services and hospital personnel for their assistance."
Day was sitting in second spot in the season-long points race as the world's premier golfers chase the $US10 million bonus jackpot.
Day's off-course issues mirrored his rollercoaster round.
After starting on the 10th hole, he had three bogeys, two two birdies and an eagle on the par-5 second to be four shots off the pace midway through the opening day.
Englishman Paul Casey and Argentine Fabian Gomez share the clubhouse lead after shooting five-under 66s.
Adam Scott was four under and in a tie for third approaching the turn, while fellow Australian Marc Leishman signed off for a three-under 68.
- AAP