Miami Marlins Minor League pitcher Ronny Fermin was suspended for 50 games by Major League Baseball after testing positive for Metabolites of Stanozolol, a performance-enhancing substance in violation of the Minor League Drug Prevention and Treatment Program, the league announced Friday.

Fermin, 19, signed a Minor League contract with the Marlins in November.

The suspension will be effective at the start of the Gulf Coast League season. Fermin is currently listed as a member of the Marlins' Rookie-level club.