The sportsman had been working on plans to take his life story to the big screen for months before he died in May (12), and producers are now pressing ahead with the project by casting Fernandez in the title role for Johnny.
The film will focus on the late boxer's traumatic childhood, which saw his father murdered before he was even born and his mother kidnapped, raped and killed when he was just eight years old.
The harrowing series of events led Tapia, who first stepped into the ring at the age of nine, to develop a lifelong drug addiction.
The five-time world championship boxer passed away at the age of 45, and autopsy results released on Thursday (23Aug12) reveal he died from heart disease exacerbated by prescription drugs - not a cocaine overdose as had been widely speculated.
The movie will be directed by Eddie Alcazar and filming is due to begin next year (13), according to The Hollywood Reporter.