“We have to remember,’’ Julien has said frequently in his two-plus seasons behind the Boston bench, “these guys aren’t machines.’’

The Bruins, though, have been almost robotic in their success lately, posting an impressive 8-1-2 record since a 4-1 loss to the Islanders Nov. 16. The club’s power play has improved dramatically, especially over the last two weeks, and its penalty killing now ranks No. 1 in the league, tied with San Jose at 85.7 percent.

Long gone, it appears, is the viral case of melancholia that pervaded the roster the first month of the season. In hindsight, Julien categorizes his club’s early inconsistency as a failure to engage emotionally.

“Emotion has a lot to do with success,’’ Julien offered Saturday morning, prior to what turned into a solid effort against the Islanders, even if the outcome fell short. “We were going out there and just playing the game, thinking that, hopefully, it would be enough to win. And if not, then [we were thinking], ‘OK, maybe the next game.’ Well, that’s not good enough.’’

A number of elements have factored into the turnaround, but one of the biggest keys was upgrading the penalty killing, which coincided with the Oct. 18 trade that sent Chuck Kobasew to Minnesota and brought in PK specialist Daniel Paille from Buffalo.

Prior to Paille’s addition, the Bruins were burned for a pair of power-play goals in three of their first seven games. In 24 games since, they have given up only six power-play goals, and never more than one per game. Their rate since Paille’s arrival has been a dazzling 92.4 percent (73 for 79). In one 13-game stretch, the Bruins allowed only one power-play goal, killing 38 of 39 (97.4 percent).

Upgrading the PK was one of general manager Peter Chiarelli’s stated objectives going into the summer. The Bruins were a mid-pack (tied 11th overall with Montreal) PK squad in 2008-09, which in part explains why Chiarelli and Co. allowed free agent P.J. Axelsson to leave for Sweden.

Laviolette, a former assistant coach with the Bruins, has his greatest challenge in net, where the Flyers have been severely lacking since the end of the Ron Hextall era, now almost a dozen years in the rearview mirror. General manager Paul Holmgren gambled that a rehabbed Ray Emery, who underwent a career makeover in Russia last season, and journeyman Brian Boucher would seal the net this season. But Emery recently underwent abdominal surgery, leaving Boucher and rookie Johan Backlund to get the job done.

On Saturday, Holmgren signed ex-Bruin goalie John Grahame, out of work since a failed Russian tour of his own last season, to a tryout contract with the Adirondack Phantoms of the AHL.

Kevin Paul Dupont can be reached at dupont@globe.com.