Mondesi, the club's top prospect and No. 33 overall per MLBPipeline.com, tested positive for Clenbuterol, a performance-enhancing substance. His suspension is effective immediately.
In a statement released by the MLB Players Association, Mondesi responded to the suspension: "Today, I agreed to accept a 50-game suspension from Major League Baseball. It is by far one of the hardest moments I have had to face in my life, but it is a decision that I accept and one that I take full responsibility for as a professional.
"I took an over-the-counter medication [Subrox-C], which I bought in the Dominican Republic to treat cold and flu symptoms. I failed to read the labeling on the medication or consult with my trainer or team about taking it and did not know it contained a banned substance. I tested positive for that banned substance, with a minuscule amount of Clenbuterol in my system, which could not have possibly enhanced my performance on the field, and now must face the consequences of that mistake.
"I apologize to my organization, my teammates, the fans and everyone who has supported me in my career. Never did I intend to take a substance that would give me an unfair advantage on the field. It is solely my mistake and there are no excuses for my carelessness in not being fully informed of what I put in my body. My goal is to work through this setback and make it back in time to help my organization compete for another World Series title."
MLB and the MLBPA reached an agreement to drop the suspension from 80 to 50 games after Mondesi showed the banned substance in a cold medicine, according to the New York Post's Joel Sherman.