"I should be OK, just in a lot of pain," Allenby said in a text message to The Associated Press.
He said he was still meeting with the FBI on Saturday evening.
Golf Channel reported during the Sony Open telecast that Allenby was in a wine bar Friday night when he became separated from his caddie and a friend from Australia. The caddie told the network that Allenby was beaten, robbed of his cellphone, cash and credit cards and driven some six miles away and dumped in a park.
He was found by a retired military man, who helped him back to his hotel at Waialae Country Club.
Contacted by Australian Associated Press, the 43-year-old Allenby said he might have been drugged in the Amuse Wine Bar in Waikiki Beach and taken to an underground garage where he was robbed and thrown into the trunk of a car.
"I didn't think I was going to survive this one," Allenby told AAP.
He said a homeless woman in the park told him she saw him thrown out of the car, which led to the scrapes on his forehead. He said the retired military man paid for a taxi to get him back to his hotel.
A Honolulu police spokesman did not immediately return for comment.
Honolulu television station KHON2 said police were investigating it as second-degree robbery.
Stuart Appleby, a fellow Australian player, said he called Allenby's hotel room Saturday morning and that Allenby was trying to reconstruct what happened. Appleby did not want to disclose what he said because "I don't know how straight his brain is."
Allenby has four PGA Tour victories, the last one in 2001. He has won 22 times worldwide, played in the Presidents Cup six times. His career was slowed in 1996 when he was seriously injured in a car accident in Spain.