The 43-year-old has said he has “no recollection” of events that unfolded last Friday after he missed the cut at the Sony Open and spent the evening in a wine bar.
Allenby has explained that he was found unconscious six miles away in a park with significant facial injuries and missing his wallet, mobile phone, cash and credit cards.
Rather than immediately return to work at the tour event in La Quinta, California, Allenby believes he would be wise to step away, having taken medical advice.
He said in a statement released by the PGA Tour: “On the advice of my personal doctor, I have decided to withdraw from this week’s Humana Challenge. This will enable me to ensure I am fully recovered prior to rejoining the PGA Tour. I anticipate a full recovery and look forward to returning in the near future.
“Once again, I would like to thank the local authorities in Hawaii as well as the PGA Tour for their assistance. I am also grateful for all the kind words of support I have received from so many people.
“Any further updates on the investigation will come from local law enforcement.”