"The difference in the two teams was that they valued checking," McLellan said. "It was really important to them. And we neglected it. Usually when that happens, the team that values it wins the game.
"It's OK to not score sometimes, but it's not OK to neglect your responsibilities defensively, and that's how I look at some of our guys right now."
Other areas have not helped the Oilers take up the slack. Their power play has been similarly inconsistent; Edmonton has scored with the extra man in two of their past 11 games.
"Too fine, too slow to shoot, too cute, not working real hard to get secondary chances," McLellan said.
The transition has introduced new faces (Lucic, Russell, Larsson and rookies Drake Caggiula and Jesse Puljujarvi) and new roles, all under a new leader and captain.
Some uncertainty showed on Tuesday, Lucic said.
"It was almost like we were kind of waiting for the first thing to happen instead of going out there and making it happen," he said. "That's something we're still learning as a young group. No matter who you're playing, you've got to get up for the games, and it starts here in this dressing room, creating that emotion before the puck drops. As the season goes on, games mean more and more, so hopefully we can learn our lesson that we need the right kind of emotion right off the start."
When Edmonton lost 2-1 at home to the Arizona Coyotes on Sunday, McLellan decided the mental fatigue of a 15-game November was affecting the Oilers. He gave his players an unscheduled day off on Monday and did not consider it a factor after the loss Tuesday.