Sammy Sosa and Mark McGwire

Sammy Sosa and Mark McGwire rejuvenated baseball in the summer of 1998 with their race towards Roger Maris' single-season home run record. McGwire hit his 62nd homerun against Sosa's Cubs, however, both players are widely suspected to have been using performance enhancing drugs at the time, casting a pall over the legitimacy of McGwire's feat. (Tribune photo by Nuccio DiNuzzo / September 8, 1998)


(Reuters) - A timeline of key Major League Baseball doping milestones:

1998

Aug 22 - A jar of androstenedione is discovered in the locker of St. Louis slugger Mark McGwire, who admits he uses the steroids precursor. McGwire goes on to hit a then Major League record 70 homers. Performance-enhancing drugs were not illegal in baseball at that time.

2001

April - MLB implements its first random drug-testing program in the minor leagues.

2002

Aug 30 - Major League Baseball's Joint Drug Prevention and Treatment Program unveiled. Policy calls for "Survey Testing" in 2003 to gauge the use of steroids among players. No one will be punished.

2003

Feb 17 - Steve Bechler, a Baltimore Orioles pitcher, dies from heat exhaustion at spring training. Over-the-counter, performance-enhancing drug Ephedra found in his system and considered by medical examiner as primary cause of death.

March 1 - Drug testing begins in Major League spring training camps.

2004

June - Drug testing of Major League players begins under the punitive phase of the Joint Drug Agreement.

December - The San Francisco Chronicle prints portions of leaked grand jury testimony given by the Giants' Barry Bonds and the Yankees' Jason Giambi. Giambi reportedly admits injecting himself with steroids and Bonds reportedly says he unwittingly may have allowed his former trainer to rub cream that had a steroid base on his legs.

2005

Jan 13 - MLB and the players association strengthen the drug program with a 10-day suspension for the first positive test, 30 days for the second, 60 days for the third, and one year for the fourth. All without pay.

April 3 - Tampa Bay's Alex Sanchez becomes first big league player to test positive under new Joint Drug Program. He is suspended for 10 days.

Aug 1 - Rafael Palmeiro is suspended for 10 days for testing positive for stanozolol, becoming the most prominent player to be penalized for steroids.

Nov 15 - Penalties for steroid use strengthened with suspensions of 50 games for a first offense, 100 games for a second and a lifetime ban for a third.

2007