In an exclusive jailhouse interview, Samuel Velez, 22, told the New York Daily News Tyson pummeled him for no reason after his friend approached the boxer for an autograph at a Brooklyn hotel early Saturday.
Velez was put in jail after the incident for an outstanding warrant.
Tyson told police the men harassed him for an autograph and that Velez threatened him by implying he had a gun when Tyson declined their request.
Velez and Alvarez-Ramos were charged with harassing and menacing Tyson, who was hit with a misdemeanor assault charge but was freed pending a future court date.
Velez said his vision is blurred and he has a badly swollen eye, bruised ribs and a banged-up mouth.