Former major league baseball player Jose Canseco admitted regret about writing Juiced, a book that detailed rampant steroid use throughout baseball.

Canseco tweeted at former Oakland A's and St. Louis Cardinals manager Tony La Russa, boy did I mess up by writing that book tell big mac I am sorry. The Big Mac reference is to former baseball player Mark McGwire, who was implicated in the book for using steroids. In the book Canseco claimed that as many as 85 percent of professional baseball players use steroids.

He also implicated Rafael Palmeiro, Jason Giambi, Ivan Rodriguez, among other players. The book was heavily criticized when it came out in 2005, but later proved to be correct in many ways once information was leaked from the BALCO case.

The outburst came after Canseco refused to take a mandatory drug test in order to play in a Mexican baseball league. He reportedly admitted to taking testosterone for a medical condition and decided to not bother taking the drug test.

Canseco spent last season as the player/coach of the Yuma Scorpions. The 47-year-old last played in the majors with the Chicago White Sox in 2001, but did have an impressive career. He was a six-time All-Star, a four-time Silver Slugger Award winner, and the AL MVP in 1988.