In this Sept. 2, 1997 file picture Andre Agassi, seen, during a news conference following his lost match against Australia's Patrick Rafter at the U.S. Open in New York. THE ASSOCIATED PRESS/Ron Frehm, File

(From L) A combo image of US tennis player Andre Agassi at the Men's French Open finals on June 9, 1991 and four years later during a third-round match on June 2, 1995 in Paris. Former tennis star Andre Agassi wore a lion mane-style wig during the 1990s to hide his baldness excerpts from his autobiography have revealed on October 31, 2009. AFP PHOTO/PATRICK KOVARIK (Photo credit should read PATRICK KOVARIK/AFP/Getty Images)

US tennis player Andre Agassi (R) congratulates his Ecuadorian opponent Andres Gomez, winner of the Men's singles of the French Open final on June 10, 1990 at Roland Garros stadium in Paris. Former tennis star Andre Agassi wore a wig held together with pins in his first Grand Slam final, excerpts from his autobiography have revealed on October 31, 2009. The hairpiece, in his famous mullet style had fallen apart the night before the 1990 French Open final, which Agassi lost to Andres Gomez. AFP PHOTO/PIERRE VERDY (Photo credit should read PIERRE VERDY/AFP/Getty Images)

US tennis player Andre Agassi hits the ball in his match against Ecuadorian Andres Gomez during the Men's French Open final on June 10, 1990 at Roland Garros stadium in Paris. Former tennis star Andre Agassi wore a wig held together with pins in his first Grand Slam final, excerpts from his autobiography have revealed on October 31, 2009. The hairpiece, in his famous mullet style had fallen apart the night before the 1990 French Open final, which Agassi lost to Andres Gomez. AFP PHOTO/PIERRE VERDY (Photo credit should read PIERRE VERDY/AFP/Getty Images)

US tennis player Andre Agassi hits the ball in his match against Ecuadorian Andres Gomez during the Men's French Open final on June 10, 1990 at Roland Garros stadium in Paris. Former tennis star Andre Agassi wore a wig held together with pins in his first Grand Slam final, excerpts from his autobiography have revealed on October 31, 2009. The hairpiece, in his famous mullet style had fallen apart the night before the 1990 French Open final, which Agassi lost to Andres Gomez. AFP PHOTO/PIERRE VERDY (Photo credit should read PIERRE VERDY/AFP/Getty Images)

FILE - In this May 21, 1989 photo, Andre Agassi hits a return during the final match against Argentina's Alberto Mancini at the Italian Open men's tennis championships in Rome. International tennis and anti-doping officials expressed disappointment Wednesday, Oct. 28, 2009, at Andre Agassi's admission that he used a banned drug and lied to escape a ban, but said it was too late to take any sanctions against the eight-time Grand Slam champion.

Andre Agassi is pictured here celebrating a win after a 1997 Davis Cup match played in Newport Beach, CA. Tennis great Agassi has admitted he tested positive for hard drugs in 1997 and lied to sporting authorities to escape a ban, according to his autobiography serialised in London-based The Times newspaper.

FILE - In this Sept. 2, 1997 file picture Andre Agassi, seen, during a news conference following his lost match against Australia's Patrick Rafter at the U.S. Open in New York. Andre Agassi's upcoming autobiography contains an admission that he used crystal meth in 1997 and lied to tennis authorities when he failed a drug test - a result that was thrown out after he said he "unwittingly" took the substance.

FILE - In this Sept. 2, 1997 file picture Andre Agassi, seen, following his match against Australia's Patrick Rafter at the U.S. Open in New York. Rafter won 6-3, 7-6 (7-4), 4-6, 6-3. Andre Agassi's upcoming autobiography contains an admission that he used crystal meth in 1997 and lied to tennis authorities when he failed a drug test - a result that was thrown out after he said he "unwittingly" took the substance.

American Andre Agassi, left, Hong Kong singer Aaron Kwok and American Pete Sampras pose before a friendly exhibition at the Venetian Hotel in Macau Sunday, Oct. 25, 2009. The two tennis greats revisited one of the sport's greatest rivalries in the 1990s. They last played in the U.S. Open final in 2002. (THE ASSOCIATED PRESS/Vincent Yu)