read this on wikipedia when was checking for any info for the game,
"
Fight Night Round 4 will feature over 40 licensed fighters. There will be several new modes such as the Legacy Mode. [2] The game's cover will feature Muhammad Ali and Mike Tyson.[3]
The following fighters have also been confirmed: Joe Frazier, Thomas Hearns, Julio César Chávez, George Foreman, Ricky Hatton, and Manny Pacquiao."