Toronto Blue Jays pitching prospect Marcus Stroman was suspended 50 games without pay on Tuesday after testing positive for a performance-enhancing drug.

Stroman, who is currently with the double-A New Hampshire Fisher Cats of the Eastern League, tested positive for Methylhexaneamine, a drug banned by the World Anti-Doping Agency.

"Despite taking precautions to avoid violating the minor league testing program, I unknowingly ingested a banned stimulant that was in an over-the-counter supplement," said Stroman in a statement. "Nonetheless, I accept full responsibility and I want to apologize to the Toronto Blue Jays organization, my family, my teammates, and the Blue Jays fans everywhere.

"I look forward to putting this behind me and rejoining my teammates."

The right-hander had two wins and a 3.38 earned-run average over eight appearances with the Fisher Cats. Stroman also had a win and a 3.18 ERA with the single-A Vancouver Canadians of the Northwest League this season.

"This suspension is unfortunate and we are disappointed by this development," said Blue Jays general manager Alex Anthopoulos. "The Toronto Blue Jays however fully endorse the Major League Baseball's drug testing policy and support the discipline taken today."

Kansas City Royals minor league first baseman Mark Donato was also suspended 50 games after testing positive for an amphetamine.

Tampa Bay Rays minor league outfielder Joshua Sale was banned 50 games after testing positive for methamphetamine and an amphetamine.

All three suspensions are effective immediately.