The AHL made the announcement in a brief news release but did not reveal details about the violation. Ross, who's in his third season with the Toronto Marlies, later issued a statement through the Professional Hockey Players' Association.
"I truly want to apologize to the entire Toronto Maple Leafs organization, my teammates, friends, family, and fans for violating the terms of the AHL/PHPA Performance Enhancing Substances Program," he said on the PHPA website. "I should have been fully mindful of anything entering my body and I understand the consequences for what has occurred. However, I did not at any time intentionally attempt to enhance my performance.
"All I can do now is learn from this and help educate other players to avoid making the same mistake I made. I look forward to putting this behind me and getting back to playing the game I love."
Ross, a 22-year-old native of Lethbridge, Alta., was drafted by Toronto in the second round (No. 43 overall) of the 2010 NHL Entry Draft. The six-foot-one 183-pound forward has four goals, three assists and 40 penalty minutes in 21 games for the Maple Leafs' AHL affiliate this season.
"The Toronto Maple Leafs organization supports the AHL Substance Abuse Program and today's decision to suspend forward Brad Ross," Maple Leafs general manager David Nonis said in a statement. "Our organization is diligent in its work to only provide our athletes supplements approved by the Banned Substance Control Group, and we've stressed the importance of staying within these parameters to maintain the integrity of what goes into their bodies.
"We are disappointed with Brad and fully support today's suspension."
Random testing was done earlier this season and the PHPA was informed of Ross's A and B test results on Monday, PHPA executive director Larry Landon said from Niagara Falls, Ont. That was followed by a 48-hour window for a possible appeal, but Ross and his agent informed the PHPA that they did not wish to go that route, Landon added.
The AHL's drug testing program began at the start of the 2014-15 season. Details on the substance that triggered the positive test were not released.
"The integrity of the program is to keep it in confidence as best we can," Landon said. "He understands he has made a mistake and is going to pay the consequence of that mistake. Unfortunately it's our first (case). Will it be our last? I don't know. I hope so, but we've all said from the get-go that it's not a witch hunt, it's a deterrent.
"We need players coming into this sport to realize that the sport is going to be clean and we need young kids coming into the system to realize that too."
In November, Maple Leafs forward Carter Ashton was suspended for 20 games by the NHL after failing a drug test. Ashton, who has split this season with the Maple Leafs and Marlies, said he inadvertently ingested clenbuterol, a prohibited substance, after using another athlete's inhaler during an asthma attack.
The AHL program is administered by doctors who supervise the NHL/NHLPA Performance-Enhancing Substances Program and the Substance Abuse/Behavioral Health Program. Ashton was the third player suspended under the NHL/NHLPA policy, following Sean Hill in 2007 and Zenon Konopka last May.
The AHL and PHPA worked in collaboration with the NHL and NHLPA to replicate many of the collectively bargained policies already in place for NHL players. In the AHL, a second positive test results in a 50-game suspension and a third positive test results in a two-year ban.
Ross will be eligible to return to the lineup March 8.
Follow @GregoryStrongCP on Twitter.