Right-hander Juan Arias was supsended for 50 days after testing positive for a performance-enhancing substance, the commissioner's office announced Thursday.
Arias, a pitcher in the Miami Marlins' organization, tested positive for metabolites of Stanozolol.
The 18-year-old Arias is on the roster of the Marlins' Dominican Summer League team. The suspension will take effect when the Dominican season begins.
In 2012, Arias pitched in 12 games for the Dominican League team and was 1-3 with a 5.23 ERA.