NEW YORK (AP) — Toronto Maple Leafs forward Carter Ashton was suspended for 20 games without pay by the NHL on Thursday after failing a drug test.

Ashton said in a statement released through the players’ union that he inadvertently ingested clenbuterol, a prohibited substance, through an inhaler during an asthma attack at practice in late August. He said he used another athlete’s inhaler twice and “incorrectly assumed that there were no problems” with the device.

Ashton added he wasn’t seeking an “athletic advantage or to knowingly violate” the drug program. He said his team doctor has since diagnosed his exercise-induced asthma and he has been prescribed an inhaler.

“As a professional hockey player, I recognize that I am responsible for what I put into my body, and I will not appeal my suspension,” Ashton said in the statement. “While I am extremely disappointed that I have let my teammates, our fans and the Maple Leafs organization down, I will work very hard during my suspension to stay in game shape so that I can help out the team when I am able to return.”

The suspension will cost Ashton $169,185. He failed to record a point in three games with the Maple Leafs this season.

Maple Leafs President Brendan Shanahan said in a statement that the organization supports the drug program and the decision to suspend Ashton.

Ashton is the third player suspended under the NHL/NHLPA policy, following Sean Hill in 2007 and Zenon Konopka in May.