Former UFC Light Heavyweight Champion Lyoto Machida has admitted to using a banned substance, according to the United States Anti-Doping Agency (USADA) and his bout with Dan Henderson has been pulled from UFC On Fox 19. A featherweight contest between Cub Swanson and Hacran Dias has been promoted to the main card. There is no word yet on which fight will take the Swanson/Dias fight on the Fox Sports 1 portion of the preliminary card. UFC On Fox 19 takes place on April 16th from the Amelie Arena in Tampa, Florida with Rashad Evans and Glover Teixeira headlining.