ESPN - Controversial Rocker says baseball knew he was using steroids - MLB

Later Monday, he told Atlanta sports talk radio station 680 The Fan that "between 40 to 50 percent of baseball players are on steroids" and "in 2000 Bud Selig knew John Rocker was taking the juice."

Last March, Rocker told ESPN Radio that, by his own guess, "less than 10 percent" of players were using illegal performance-enhancing substances while he was in the majors.
There's more to the article but here's what you have to really look at. The guy has changed his story and just seems to be seeking attention. Apparently Pros vs. Joes won't have him back. He is also saying he failed a drug test and Selig let it slide. An interesting read about a deranged asshole.