The National Hockey League has ruled that forward Dean McAmmond is ineligible to play for the Calgary Flames for the remainder of the season after determining that his trade from the Calgary Flames violated the terms of the collective bargaining agreement, ESPN The Magazine's E.J. Hradek has learned.

McAmmond will receive his salary, and will be allowed to practice with the team and participate in team functions.

The CBA clause states that a player traded by a club within four weeks prior to the waiver draft may not be re-acquired by the club within the same season. McAmmond was acquired by the Avalanche on Oct. 1 as part of the five-player trade that sent Chris Drury to Calgary. The waiver draft was Oct. 4.

The rule was implemented to prevent NHL teams from "hiding" players for the waiver draft then getting them back after the waiver draft is completed.

After meeting with the NHL Players' Association and the teams, the NHL determined the trade did not violate the spirit of the rule.

"I know there are a lot of questions. I wish I had more answers," Flames general manager Craig Button said Thursday night. "Once we have more answers, I will be able to give you a full statement. As of right now, we are trying to find a resolution to the Dean McAmmond trade.

"An unfortunate circumstance occurred. The league is working very hard to find a solution. Once we find that solution, we will have further comment."

McAmmond missed the first 23 games this season with a back injury and never really got into a rhythm with his new team. He had 10 goals and eight assists in 41 games, but was a healthy scratch in five of the past 15 games.

Information from SportsTicker was used in this report.