Rowell, a corner infielder who is in the process of converting to pitching this season, received a 50-game suspension after a second violation of the Minor League Drug Prevention and Treatment Program for a drug of abuse.
The 23-year-old last played for Double-A Bowie, but he's currently on the roster of the Orioles' short-season affiliate, Aberdeen, so his ban will be effective at the start of the IronBirds' season on June 18. He had yet to appear in a Minor League game this season.
The Sewell, N.J., native began a throwing program this spring and the Orioles expected he would transition to pitching in extended spring training games and potentially in the Minors this season.
He split last season between Double-A Bowie and the Gulf Coast League Orioles, for whom he had one homer and 18 RBIs in 58 games.
Minor Leaguers are warned after testing positive for a drug of abuse and then suspended after a second violation. The Commissioner's Office does not disclose the specific substance in these cases. Substances considered "drugs of abuse" by Major League Baseball include cocaine, marijuana, heroin, LSD, ecstasy and other opiates.
The Office of the Commissioner has suspended 41 players this year for violations of the Minor League Drug Prevention and Treatment Program.