The NHL on Thursday suspended Buffalo Sabres forward Zenon Konopka for 20 games for violating the terms of the NHL/NHLPA performance enhancing substances program.

Konopka, 33, is an unrestricted free agent. He said in a statement he has no plans to retire, so should he be picked up by another NHL club, the suspension will be served at the beginning of the next contract.

The Niagara-on-the-Lake, Ont., native has 12 goals and 18 assists, with 1,082 penalty minutes, in 346 NHL games. He's played for seven different clubs, ending the most recent season with the Buffalo Sabres.

Konopka said he took an over-the-counter substance that unknowingly contained a banned substance.

Under the terms of the collective bargaining agreement, the suspension is accompanied by mandatory referral to the NHL/NHLPA program for substance abuse and behavioural health for evaluation and possible treatment.

Konopka's statement released through the NHLPA, reads as follows:

"I deeply regret that I have tested positive for a prohibited substance in violation of the NHL/NHLPA Performance Enhancing Substances Program.  I accept full responsibility for this error. As a professional athlete I am responsible for what I put in my body, and I am to blame for this mistake. 

"I want to make it clear that this violation occurred because I ingested a product that can be purchased over-the-counter and which, unknown to me, contained a substance that violated the program. Unfortunately, I did not take the necessary care to ensure that the product did not contain a prohibited substance. I want to stress, however, that I did not take this substance for the purpose of enhancing my athletic performance."

With files from CBCSports.ca