Although 48-year-old Gooding recently said Simpson was one of the "hardest characters" of his career, Gooding said there was "no reason to" meeting the former football star, now 68.
"I didn't want to. There was no reason to," he told People during the FX Winter TCA Press Tour Saturday.
"If I was playing him today, I'd have to put on a lot of weight," he continued, adding the current Simpson is different than the one he needed to depict in the FX series, premiering Feb. 2.
"He was this flamboyant, charismatic, movie star, marquee-athlete. I needed that arrogance," he said. "That was where my focus was."
Variety reports Gooding said playing that arrogant marquee-athlete was the most difficult of his career.
"It was six months of an emotional roller coaster," he said at the same press tour.
Of meeting the now-incarcerated Simpson, he explained being in jail changes people, making them truly believe whatever reality they want.
"I have friends who are incarcerated and it breaks a man's spirit," he told Variety. "At some point you start to believe whatever reality, even if it's not truth."
Despite having "no desire" to meet Simpson in preparation for his most recent role, Gooding said if executive producer Ryan Murphy wanted to continue following the story of O.J. Simpson to the present day, then he will consider meeting the series' real-life subject.