Silverio, 19, tested positive for metabolites of Stanozolol, a performance-enhancing substance in violation of the Minor League Drug Prevention and Treatment Program.
His suspension will be effective immediately upon his signing with a Major League organization.
Silverio has never played in a Minor League game.
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. It was a main topic of the book Game of Shadows for its alleged usage amongst baseball players.
The suspension comes a day after the Commissioner's Office suspended Tampa Bay's Tim Beckham, the No. 1 overall pick of the 2008 Draft. Major League Baseball has suspended 39 players in 2012 for violations of the Minor League program.