E! News has reached out to the "Baywatch" actor's team for comment and has not heard back.
The 36-year-old, who had also sparked health concerns in 2013 after he suffered an accident at his house that resulted in a shattered jaw, has been vacationing in the Spanish islands for the past couple of weeks.
On Aug. 1, one day before the swimming pool incident, Efron joined his longtime friend Martin Garrix onstage behind the DJ booth at the Dutch performer's show at the Ushuaïa Ibiza venue.
"Like every week, Martin Garrix delivered an exceptional performance that left us all in awe," read a post shared on the beachfront club's Instagram page, alongside photos and videos from the night. "To top it off, Zac Efron joined him on stage during "Smile."
