Canseco, in 2008. (Michael Buckner / Getty Images)

Canseco, trying to make a comeback at 47, told Plinio Escalante, president of the Mexican League, that he had used testosterone, according to an ESPN Desportes report. Canseco said he did not take a drug test and tweeted that he uses “prescription medication for low testerone [sic],” calling it “very important to my health.”

Canseco used Twitter to tell his side of the story, tweeting first: “How can I test positive when I never took any test don't believe everything the media tells you.the truth always comes out I am not using any illegal substanced. Don't be so quick to judge till you here the truth that's a sure sign of ignorance hatred and jealousy.”

Later, he divulged the medical condition: “Doctors have been monitoring me ever since to make sure my levels are normal.that's why I don't use any illegal substances its prescribed” and “All I am on is prescription medication for low testosterone .legal and very important to my health. ... U should all get checked for low testosterone over 40 .It leads to heart disease depression metabolic Syndrome diabetes cognitive disorders”

Althugh the Mexican League is a Triple-A affiliate of Major League Baseball, its teams are not tied to MLB teams. Canseco seems to see a conspiracy afoot.

Someone big wants me out of Mexico .question is who and y

— Jose Canseco (@JoseCanseco) March 8, 2012

Canseco last played in the major leagues for the Chicago White Sox in 2001 and tried out for the Quintana Roo Tigers on Feb. 12, according to the team. He was the 1988 American League MVP and played for seven MLB teams over a 17-year career. He admitted using anabolic steroids in 2005 and wrote a book in which he accused 85 percent of major leaguers of using banned substances. He walked that back with a tweet to one of his former managers.

@TonyLaRussa boy did I mess up by writing that book tell big mac I am sorry

— Jose Canseco (@JoseCanseco) March 8, 2012