Roberto Clemente Jr. told the New York Daily News he met Luiz Perez after undergoing a second operation for chronic pain in his right knee in 1987 while with the San Diego Padres' organization.
Perez told Clemente Jr. he needed to start taking B-12 injections, along with steroids testosterone and androstendione to help increase his strength.
"He might as well have been speaking Chinese to me," Clemente Jr. told the newspaper. "I didn't know what they were, but he said they would help me, and I said, 'OK, great.' Today you know what those things are, but then I couldn't even imagine anything like steroids, which could make you feel great and at the same time could be killing you."
Clemente Jr., who was 6 when his Hall of Fame father died in a plane crash in 1972, estimates he got about 150 shots, and he added 20 pounds of muscle.
"I didn't think I was doing anything wrong. I was just trying to rehab my knee," the News quoted him as saying.
Clemente Jr. stopped taking the shots after almost a year when he left to play winter ball in Venezuela. Within a year, he began feeling tingling sensations at the site of the injections.
In the winter of 1989, he signed with the Orioles' organization, but his career was over at 24 because of a back injury. He never made it above Single-A.
Manager Dusty Baker and pitching coach Larry Rothschild said they will make a decision today.
Prior has been on the disabled list with elbow inflammation.
He has an 87-79 record in 12 major league seasons with the Rangers, Cardinals, Red Sox, Rockies, Astros and Marlins.
Last season, he was 3-3 with a 5.95 ERA with Houston and Florida.