Muhammad Ali's life will be celebrated with a traditional Islamic prayer service after thousands of tickets were snapped up for the boxing great's funeral on Friday.
Members of Ali's family will attend the Jenazah at the Freedom Hall in his home town of Louisville, Kentucky, where Ali made his professional debut with victory over Tunney Hunsaker in 1960.
He also fought his last boxing match in Louisville at the venue, defeating Willi Besmanoff in November 1961.
Up to 15,000 people are expected to attend the huge public memorial at the KFC Yum! Centre in Louisville, as it emerged some ticket-holders were looking to profit from the free event by selling tickets online.
Bob Gunnell, spokesman for the Ali family, said: "I'm personally disgusted and amazed that someone would try to profit off of Muhammad Ali's memorial service.
"I hope that those buying tickets or trying to buy tickets would stop those efforts by not purchasing.
"Muhammad Ali wanted this to be a free event, an event that was open to all."
Tickets for the funeral quickly sold out when they were released on Wednesday after long queues formed around the KFC Yum! Centre.
US president Barack Obama will miss the funeral because he is attending his daughter Malia's high school graduation ceremony, the White House said.
Mr Obama and his wife Michelle are sending a letter to be read at the service, where White House senior adviser Valerie Jarrett - who knew Ali personally - will represent the president.
A procession will take place through the streets of Louisville before a private burial at Cave Hill Cemetery.
Ali died in Phoenix, Arizona, last Friday aged 74. The three-time world heavyweight champion had been admitted to hospital with a respiratory condition having suffered with Parkinson's disease for 32 years.
The cause of death was septic shock due to unspecified natural causes, his family said.
Two of Ali's daughters, Rasheda and Maryum, will speak at the funeral, along with Ali's widow Lonnie, former US president Bill Clinton, American actor Billy Crystal and Malcolm X's daughter Attalah Shabazz.
Turkish president Recep Tayyip Erdogan and King Abdullah II of Jordan will no longer address the congregation, a spokesman for the Ali family said, but they are expected to attend the service, which will be live-streamed on the internet.
Former world heavyweight boxing champion Lennox Lewis and Hollywood actor Will Smith - who portrayed Ali in the 2001 film about the boxer's life - will be among the pallbearers.
The others will be Jerry Ellis - the brother of Jimmy Ellis, Ali's former sparring partner and fellow world heavyweight champion - and Ali's cousins John Grady and Jan Wadell, nephew Ibn Ali, former brother-in-law Komawi Ali and family friend John Ramsey.