Red Sox left-hander Francisco Tena was suspended for 50 games on Thursday after testing positive for an anabolic steroid.
The Office of the Commissioner of Baseball said Tena tested positive for metabolites of Stanozolol, a performance-enhancing substance in violation of the Minor League Drug Prevention and Treatment Program.
Tena, 18, has yet to make his Minor League debut, although he is on the roster of Boston's Rookie-level Dominican Summer League affiliate after signing with the Red Sox in December. The suspension will be effective at the start of the DSL season.
Stanozolol is a synthetic anabolic steroid derived from testosterone that is sometimes prescribed by veterinarians to encourage muscle growth, red blood cell production, bone density and to stimulate the appetite of weakened animals. Tena is the fourth Minor Leaguer to test positive for the substance this year.
Major League Baseball has suspended 15 players this year for violations of the Minor League drug program.