Heavy weight boxer Muhammad Ali seen after knocking-out his British challenger Richard Dunn in the fifth round of their fight, in Munich, Germany, on May 25, 1976. Born as Cassius Clay, boxing legend Muhammad Ali, dubbed as 'The Greatest,' died on June 3 in Phoenix, Ariz., at the age of 74. (EPA)

A Muhammad Ali robe is displayed at the "I Am The Greatest, Muhammad Ali" exhibition at the O2 arena, which hosts high profile boxing fights in London, on June 4. (Matt Dunham/Associated Press)

Muhammad Ali and Floyd Patterson pose after a pre-fight physical in New York, on Sept. 11, 1972. (Don Hogan Charles/The New York Times)

Filipino boxing aficionado Marco Jose Revilla pays respect to an artwork by Monica Jane Valerio depicting Muhammad Ali inside the 'Ali Mall', the country's first mall named after the legendary boxing champion displayed in Quezon City, northeast of Manila, Philippines, on June 4. (Mark R. Cristino/EPA)

Muhammad Ali poses with gloves in this undated portrait. (Action Images/Sporting Pictures)

Muhammad Ali yells during a news conference in New York on Aug. 29, 1974. Ali, the magnificent heavyweight champion whose fast fists and irrepressible personality transcended sports and captivated the world, has died according to a statement released by his family on June 3, 2016. He was 74. (Ron Frehm/Associated Press)

US boxer Muhammad Ali (left) taking on Floyd Patterson at the Las Vegas Convention Center in Las Vegas, Nev., on Nov. 22, 1965. (Las Vegas News Bureau via EPA)

Muhammad Ali shouts during the weigh-in for his fight against Joe Bugner at Caesars Palace in Las Vegas, Nev., on Feb. 14, 1973. (Las Vegas News Bureau via EPA)

Heavyweight boxing champion Cassius Clay arrived at his Boston training camp to launch final preparations for the title rematch with Sonny Liston. The champion mugged a bit for the benefit of the patrons of his training site ar the Schine Inn at Chiopee, and scrawled on posters advertising the fight; "Bear On The Loose." Clay's pet name for Liston is "The Bear." (Associated Press)

Young heavyweight boxer Cassius Clay, who later changed his name to Muhammad Ali, points to a sign he wrote on a chalk board on Nov. 15, 1962 in his dressing room before his fight against Archie Moore in Los Angeles. (Harold P. Matosian/Associated Press)

Former heavyweight boxing champion Muhammad Ali addresses a gathering at a Black Muslim convention in Chicago on Feb. 25, 1968 . (Associated Press)

Muhammad Ali with family at his training camp in Deer Lake, Pa., on Aug. 24, 1973. Belinda Boyd, Ali’s wife, is at right; their children are Muhammad Jr., 1; twin daughters Rasheda and Jamillah, 3; Maryum, 5. (William E. Sauro/The New York Times)

Muhammad Ali, or Cassius Clay at the time, beats his chest in triumph after toppling Britain's Beatles at his training camp in Miami Beach, Fla., on Feb. 18, 1964. The Beatles, left to right: Paul McCartney; John Lennon; George Harrison and Ringo Starr, were on Holiday in the resort after their American tour. (Associated Press)

Muhammad Ali joking with a baby during a work out for his fight against Ron Lyle at the Tropicana in Las Vegas, Nev., on May 12 1975. Born Cassius Clay, boxing legend Muhammad Ali, dubbed as 'The Greatest,' died on 03 June 2016 in Phoenix, Ariz., at the age of 74. (Las Vegas News Bureau via EPA)

Muhammad Ali jokes with television sports commentator Howard Cosell before the start of the Olympic boxing trials, in West Point, NY., on Aug. 7, 1972. (Associated Press)

Muhammad Ali spars with a young admirer at the Elma Lewis benefit held at the Hynes Auditorium in Boston. (Bill Curtis/Globe Staff)

Muhammad Ali at Logan airport in Boston, talked to a crowd from his bus while changing planes. (John Blanding/Globe Staff)

Muhammad Ali trains at his camp in Deer Lake, Pa., on Jan. 17, 1974. Ali, a three-time world heavyweight boxing champion whose brash self-confidence and personal convictions made him the most charismatic and controversial sports figure of the 20th century, died in Phoenix on June 3, 2016. He was 74. (Robert Walker/The New York Times)

Muhammad Ali watches as defending world champion George Foreman goes down to the canvas in the eighth round of their WBA/WBC championship match in Kinshasa, Zaire on Oct. 30, 1974. (Associated Press)

Joe Frazier (right) lands a left hook on Muhammad Ali during the first of their three epic battles at Madison Square Garden in New York City on March 8, 1971. The Fight of the Century (also known as The Fight) is the title boxing writers and historians have given to the boxing match between champion Joe Frazier (26-0, 23 KOs) and challenger Muhammad Ali (31-0, 25 KOs). (Action Images)

A large crowd turns out as Muhammad Ali visited Harlem on Dec. 9, 1974. (Neal Boenzi/The New York Times)

Muhammad Ali evades a left from Joe Frazier during their title bout, the “Fight of the Century,” at Madison Square Garden in New York, on March 8, 1971. Five years after being stripped of his titles for refusing to register for the draft, Ali suffered the first defeat of his career here. Ali died in Phoenix on June 3. (Larry C. Morris/The New York Times)

Joe Frazier is directed to a corner by referee Arthur Marcante after Frazier knocked down Muhammad Ali during the 15th round of the title bout in Madison Square Garden in New York on March 8, 1971. Frazier won the bout over Ali by decision. (Associated Press)

Muhammad Ali (formerly Cassius Clay) trains at his Pennsylvania mountain retreat in Owigsburg on Aug., 27, 1974 for his fight against George Foreman in Zaire. (Action Images)

Philippines President Ferdinand Marcos, left, applauds as challenger Joe Frazier, right, makes some remarks about world champion Muhammad Ali, second from left, during their call on Marcos at the Malacanang Palace in Manila, Philippines on Sept. 18, 1975. (Jess Tan/Associated Press)

Spray flies from the head of challenger Joe Frazier as heavyweight champion Muhammad Ali connects with a right in the ninth round of their title fight in Manila, Philippines on Oct. 1, 1975. (Mitsunori Chigita/Associated Press)

Moroccan King Hassan II (right) decorating former World Heavyweight Champion Muhammad Ali during a ceremony in the Royal Palace in Rabat on Jan. 15, 1998. (Abdelhak Senna/AFP/Getty Images)

Argentinian boxer Sergio "Maravilla" Martinez (left) and the president of the World Boxing Council, Jose Sulaiman (right), place the crown of "King of Boxing" on former American boxer Muhammad Ali during the 50th Convention of the World Boxing Council in Cancun in this Dec. 3, 2012. (Victor Ruiz Garcia/REUTERS)

American swimmer Janet Evans passes the Olympic flame to Muhammad Ali during the 1996 Summer Olympic Games Opening Ceremony in Atlanta on July 19, 1996. (Michael Probst/Associated Press)

Muhammad Ali, reknown as 'The Greatest' fighter of all times, poses next to a Wheaties 'The Breakfast of Champions' poster during the unveiling of the 75th Anniversary cereal box in his honor in New York, on Feb. 4, 1999. 'Muhammad Ali is quite possibly the most recognized sports figure of our time,' said Wheaties market manager Jim Murphy. 'That's why we are especially proud to recognize him on our box during our 75th anniversary celebration.' (Bebeto Matthews/Associated Press)

Orson Welles (from left), US actor-singer Dean Martin, and Sports announcer Howard Cosell laughing at US boxer Muhammad Ali during the Dean Martin Roast of Muhammad Ali at the MGM in Las Vegas, Nevada, on Jan. 18, 1976. (Las Vegas News Bureau via EPA)

Muhammad Ali is greeted in downtown Kinshasa, Zaire on Sept. 17, 1974 who was in Zaire to fight George Foreman. (Associated Press)

Boxing legend Muhammad Ali stands with his wife Yolanda as he is introduced before the welterweight fight between Floyd Mayweather Jr. and Shane Mosley at the MGM Grand Garden Arena in Las Vegas, Nevada on May 1, 2010. (Steve Marcus/Reuters)

WBC and WIBA super middleweight champion Laila Ali is kissed by her father, boxing great Muhammad Ali, at the MCI Center in Washington on June 11, 2005. (Jason Reed/Reuters)

President George W. Bush awards boxing legend Muhammad Ali with the Presidential Medal of Freedom, as Ali's wife Lonnie watches, during a ceremony in the East Room of the White House in Washington on s Nov. 9, 2005. (Kevin Lamarque/Reuters)

Men pass a large sign by an escalator near the entrance of the "I Am The Greatest, Muhammad Ali" exhibition at the O2 arena, which hosts high profile boxing fights in London, on June 4. Ali, the magnificent heavyweight champion whose fast fists and irrepressible personality transcended sports and captivated the world, died according to a statement released Friday by his family. He was 74. (Matt Dunham/Associated Press)

Muhammad Ali tapes his right hand for a training session at his camp in Deer Lake, Pa., on Jan. 17, 1974. (Robert Walker/The New York Times)

US boxing great Muhammad Ali poses during the Crystal Award ceremony at the World Economic Forum (WEF) in Davos, Switzerland on Jan. 28, 2006. (Andreas Meier/Reuters)

Heavyweight boxing champion Muhammad Ali stands over fallen challenger Sonny Liston in Lewiston, Me., on May 25, 1965. (John Rooney/Associated Press )

A flower placed on display as a tribute to the life of heavyweight boxer Muhammad Ali at the "I Am The Greatest, Muhammad Ali" exhibition at the O2 arena, which hosts high profile boxing fights in London, on June 4. Ali, the magnificent heavyweight champion whose fast fists and irrepressible personality transcended sports and captivated the world, died according to a statement released Friday by his family. He was 74. (Matt Dunham/Associated Press)