In addition, Calgary coach Jim Playfair was fined US$25,000 and the Flames' organization was fined $100,000. McLennan was given a match penalty for his slash, which occurred at 17:01 of the third period. There were several other scraps and penalties in the closing minutes of the game, which the Red Wings won 5-1.
"In our pre-playoff conference calls with the coaches and general managers of the respective organizations, we addressed a number of topics - and one of them was actions late in the game when the score was out of hand," Colin Campbell, NHL's senior executive vice-president and director of hockey operations, said in a statement.
"The coach and the organization must be held accountable for the players' actions."
Calgary needs a win in Game 6 on Sunday to force a deciding game in the best-of-seven first-round series.
The Flames recalled goalie Brent Krahn from their AHL affiliate in Omaha.