Johnson teamed with Larry Bird and author Jackie McMullan on the soon-to-be released "When the Game Was Ours." In the book, Johnson accuses Thomas, his boyhood friend, of questioning his sexuality in 1991 when he was diagnosed with HIV.
"My brother (Gregory) died of HIV, AIDS, drug abuse, so I knew way more about the disease because I was living with it in my house," Thomas told the magazine.
Johnson also said he joined Michael Jordan and others in blackballing Thomas in his attempt to join 1992 Olympic Dream Team.
"Isiah killed his own chances," Johnson said. "Nobody on that team wanted to play with him."
"I wish he would have had the courage to say this stuff to me face-to-face, as opposed to writing it in some damn book to sell and he can make money off it," Thomas said.