Slugging first baseman Jonathan Singleton issued a statement through his agency on Thursday accepting a violation of Minor League Baseball's drug policy, according to ESPN.com, which first reported the news.
Major League Baseball confirmed the reports in a release on Wednesday evening.
"I was informed today that I have tested positive for marijuana," Singleton said in the statement. "As a result, I am being suspended for the first 50 games of the 2013 season. I accept the penalty and take full responsibility for my actions. I apologize to my parents, the Houston Astros and [general manager] Jeff Luhnow.
"The Astros have been nothing but supportive of me and good to me in my short time with the organization. My hope is to use this as a learning experience and spend the rest of my career proving to myself and the baseball community that this was a lapse in judgment, and is not in any way indicative of my character or my dedication to baseball or to my team."
In a statement, Astros general manager Jeff Luhnow said, "We are disappointed in the decisions that Jonathan made leading up to this positive test. Jonathan has expressed regret for his decision and we expect he will take the necessary steps to ensure this doesn't happen again. He has owned up to his actions and that is a necessary first step. The Astros will support Jonathan through this difficult time, and we hope this example will prevent other athletes from making similar decisions."
Singleton was traded from Philadelphia to Houston in the July 2011 deal involving All-Star outfielder Hunter Pence. In his first full season in the Astros system last year, Singleton batted .284 and established career highs in home runs (21), doubles (27) and RBIs (79).
Now 21, the left-handed hitter was a 2009 eighth-round draftee of the Phillies. He was expected to begin his fifth pro season at Triple-A Oklahoma City, one step from the Majors.
The severity of Singleton's suspension -- 50 games -- indicates a second positive test for a drug of abuse, which is how marijuana is categorized under Major League Baseball's Joint Drug Prevention and Treatment Program. A player is given a warning for a first positive test.
Singleton's is the first Minor Leaguer suspended in 2013.