In the week preceding the opener, Commissioner Bud Selig authorized an investigation into steroid use in baseball, citing the "specificity of the charges" in the book "Game of Shadows." The book details alleged use of performance-enhancing substances by Bonds and other athletes.
Bonds has denied knowingly using steroids. In grand-jury testimony obtained by the San Francisco Chronicle, he said substances identified by federal agents as steroids were described to him as flaxseed oil and arthritic balm. In the three years baseball has tested for steroids, Bonds has not tested positive.
"Do I believe he has used steroids?" Canseco said. "There's no doubt about it."
As his career ended -- and not by his choice -- Canseco reinvented himself as a whistle-blower. In a 2002 interview with Sports Illustrated, eight months after his final major league at-bat, Canseco estimated that 85% of major leaguers used steroids, a figure widely dismissed as ludicrous.
Last year, in his book "Juiced," he described his steroid use and fingered several ex-teammates, including his erstwhile "Bash Brother" McGwire and Rafael Palmeiro. Denials followed, and with them accusations of Canseco skirting the truth to sell books.
As Congress pressured baseball to curb steroid use, the three men testified in Washington that spring. McGwire said, repeatedly, "I'm not here to talk about the past." Palmeiro declared, "I have never used steroids. Period."
McGwire had retired by then. Palmeiro failed a steroid test later that year. Canseco says he is working on a "no holds barred" movie adaptation of "Juiced."
So how much does Canseco believe his comments and his book account for Selig's decision to launch the investigation?
"Probably everything," Canseco said.
Canseco said he would be happy to speak with former Sen. George Mitchell, appointed by Selig to lead the investigation. However, Canseco said, he has not heard from Mitchell, or anyone else involved in the investigation.
"They can't talk to me," Canseco said. "I'm off limits. No one involved with Major League Baseball -- coaches, clubhouse kids, players, owners or managers -- can speak with me. It's an unwritten law they have."
Selig denied any such directive exists, unwritten or otherwise. He said Mitchell alone determines whom to speak to, and when.
"This will be a very comprehensive investigation," Selig said. "The senator is free to contact anybody and everybody connected with this issue."