Matt Duchene of the Avalanche took advantage of a botched Bruins breakout to score the winning goal.
Matt Duchene of the Avalanche took advantage of a botched Bruins breakout to score the winning goal.WINSLOW TOWNSON FOR THE BOSTON GLOBE/Boston Globe

In Game No. 15, the Bruins finally rolled out the defense they had planned to see at the start of training camp. After missing all of the preseason and the first 14 games, Dennis Seidenberg made his season debut in Thursday's 3-2 loss to the Colorado Avalanche.

Seidenberg did not look out of place. In 15:34 of ice time, the hard-nosed defenseman was credited with a game-high six hits and two blocked shots. He was not on the ice for any goals against.

Seidenberg's return, however, did not address the shortcomings of the defensive six-pack. Mobility and skill are not among this group's trademarks. Seidenberg's game does not highlight either characteristic.


"My role is playing my brand of hockey, which is playing solid defensively and penalty killing," Seidenberg said. "Just making simple plays, playing physical hockey, and winning my battles."

Seidenberg's skill set overlaps with three of his fellow defensemen's approaches. The defense-first Seidenberg has like-minded teammates in Zdeno Chara, Adam McQuaid, and Kevan Miller.

Among Thursday night's corps, Colin Miller and Torey Krug — the latter having missed the last two practices because of an undisclosed ailment — were the two defensemen who are good at skating, moving the puck, and igniting the transition game.

Miller and Krug need more of the same.

"Puck movement from the back end," coach Claude Julien said when asked how his team could improve its breakouts. "Where is the improvement? It's there sometimes. It is there. Tonight it wasn't. So we've got to be a little bit better with that, and it goes back to what I said: consistency in our game. You see it one night. You don't the next."

Two of Colorado's goals came off misfired attempts to break the puck out of the defensive zone. In the final minute of the second period, McQuaid tracked down the puck in the right corner. While under forechecking pressure, he tried to chip the puck off the right boards and out of the zone. He did more than that. McQuaid muscled the puck all the way down the rink and was called for icing.


Matt Duchene won the following faceoff against David Krejci. By winning the draw, Duchene triggered a set play. Erik Johnson touched the puck to Francois Beauchemin at the point. Joonas Kemppainen hit the deck to block Beauchemin's shot. The puck glanced off Kemppainen's skate, changed direction, and fluttered past a helpless Tuukka Rask at 19:31, tying the game at 2-2.

In the third period, it was Kevin Miller's turn to botch the breakout. After taking a handoff from Rask in the right corner, Miller stickhandled for several strides up the ice. This allowed Ben Street to hustle from the top of the crease and close on Miller. Because of Street's heavy forecheck, Miller had nowhere to go except up the boards.

But Mikhail Grigorenko was stationed along the wall to seal off Miller's chip. It went poorly from there. As Grigorenko attacked the net, Chara was trapped in no-man's land. Before Chara could make a decision, Grigorenko snapped a cross-body pass to a streaking Duchene. The skilled forward made the Bruins pay by snapping the game-winner past Rask at 6:49 of the third.

Two sputtering breakouts. Two goals against.

"It's not how it should be," McQuaid said of the team's tendency of allowing mistakes to manifest on the scoreboard. "There's going to be times in the game when things are going to happen. It's how you react to them. For some reason, at times we need to have that follow-up shift, and we don't find it. We've got to look for it and bring it to our game."


The breakout failed the Bruins last season. Opponents knew to choke off the Bruins by deploying two forecheckers. Because it took the Bruins so long to advance the puck out of their end, they couldn't get to their rush game consistently enough.

This season, their transition game has flashed in bursts. But not regularly. Certainly not on Thursday against the Avalanche.

The Bruins looked sharp in the first 10 minutes. It's because they had their legs in center ice and attacked the Colorado net in waves.

But when their breakout sputtered, so did their slingshot transition game in the neutral zone. The Avalanche didn't even need to send in two forecheckers. They disrupted the Bruins enough with just one forechecker and gummed up center ice with three men wide.

Had the Bruins broken the puck out cleanly, they would have had enough speed through the neutral zone to break down Colorado's formation. They didn't do that. They didn't build the foundation of their game. They paid for it with their fifth loss in six games on home ice.

Seidenberg should improve with more games. If so, he'll command more ice time and take away minutes from Kevan Miller (18:21). That might not be good enough. The Bruins don't just need help on defense. They require a specific kind of reinforcement: a mobile, cool-under-fire, puck mover to turn flare-ups into non-events.


Perhaps Joe Morrow and Zach Trotman, who were healthy scratches on Thursday, will earn their coaches' trust. Or maybe general manager Don Sweeney will secure help from outside.

The Bruins have three lines of capable scorers. But their games shrink when their defensemen can't get them the puck.

Fluto Shinzawa can be reached at fshinzawa@globe.com. Follow him on Twitter @GlobeFluto.