DALLAS — He finished his shift, because of course he did.

However serious Bruins defenseman Zdeno Chara’s lower-body injury is — and it sure didn’t look like a day-to-day deal, given the way his left knee buckled — Big Z once again proved he’s tough.

After wrenching that knee when he checked ex-Bruin Carl Soderberg with 1:07 left in the first period of Wednesday’s 6-3 loss in Colorado, Chara doubled over. But briefly. He was on the ice to defend Nathan MacKinnon, Mikko Rantanen, and Gabriel Landeskog, so grimace all you want, but go, Z, go. Duty called.


Making the hit at his own blue line, Chara pivoted painfully back toward defense partner Matt Grzelcyk for a regroup, glided slowly up the ice, then back again as Colorado regained possession. Thankfully for Chara, his laborious legwork didn’t last longer than 27 seconds. MacKinnon coughed up the puck in the Bruins’ zone, and Jake DeBrusk hit the turbos from center ice for a solo break-in.

Ahead, 2-1, at the time, with 40 seconds left in the first, the Bruins were pumped. They played the final 40-plus minutes without the big man, losing a lead they extended to 3-1 on a DeBrusk tip-in. Five unanswered goals, and then a Trencin-sized trench of concern for the 41-year-old captain.

The club — which canceled its practice Thursday — announced Chara was en route to Boston to be checked out by team doctors. Standard procedure for a wrenched knee is an MRI, which would reveal any damage to Chara’s ligaments.

With no Big Z in Big D — the Boston backline could look like this against the Dallas Stars on Friday:

Torey Krug-John Moore

Grzelcyk-Steven Kampfer

Jeremy Lauzon-Jakub Zboril

That’s all lefties besides Kampfer. Lauzon would be playing his sixth NHL game; Zboril his first. To this eye, that lineup means 25-or-so minutes for Krug (still finding his way after missing most of the offseason, preseason, and first month), Moore, and Grzelcyk. That adds up quickly.


New to the equation, as of Thursday afternoon: call-up Connor Clifton, a right shot and former Quinnipiac captain in his second year with the Providence Bruins. Handedness aside, Zboril (13th overall in the 2015 draft) is ahead of Clifton (133rd overall, Phoenix, 2013) in pedigree.

With Brandon Carlo still in Boston (upper-body injury of undisclosed severity), the most immediate help would come from Kevan Miller, sidelined the last four weeks with a busted hand. The club expected the rugged defender to be back in 4-6 weeks, so a return Saturday would be early. Miller has returned to skating with the team but may be out a few more days at least.

Charlie McAvoy, ready to shine as Chara’s partner in his second season, has been out as long as Miller (Oct. 18) with post-concussion issues. Similar deal with Urho Vaakanainen, the 2017 first-round pick who served an encouraging game-plus before he was KO’d Oct. 23 in Ottawa.

Consider what the Boston defense pairings looked like on paper seven weeks ago:





The Bruins started the year with too many defensemen — eight, for six jobs — but were cautious not to call it a wealth or a surplus. They wanted a competitive training camp, but more so insurance in case the odd injury popped up. Blue-line bumps were a reason they didn’t make it out of the second round last season (someday, Carlo will appear in a playoff game).


Not yet a quarter of the way through the season, the blue line needs all the help it can get.

“It’s our whole right side, for one thing, you know?” coach Bruce Cassidy said of those hors de combat. “And now you’re talking about your top guy on the left side. Your second guy on your left side, Krug, is really still finding his game. He missed a lot of time. You’ve pretty much got your whole D-corps out.

“We’ve got to be careful in terms of how we talk to that group. By the same token, it’s their opportunity to play. We don’t make excuses.”

■ Wednesday wasn’t a great night for the Patrice Bergeron line, which lost on both the scoreboard and scoresheet to the MacKinnon trio. Boston’s 63-37-88 produced three points, nine shots, and six penalty minutes. Colorado’s 92-29-96 registered six points, nine shots, and two PIMs.

■ A string of typically orderly patrons marched to the penalty box: David Pastrnak, David Krejci, and Bergeron. All went for hooking, one of Bergeron’s coinciding with Rantanen selling the call. Colorado cashed in all three of its power-play chances.

■ Goals like DeBrusk’s breakaway don’t happen too often at five on five in the tight-checking NHL. DeBrusk was alone with the puck for about 120 feet. He said he had never seen that much open ice on a break, not in the pros or junior.


■  The Stars (9-7-2), who lost a 2-1 OT game at TD Garden on Nov. 5, have been off since losing by the same score at Columbus on Monday.

After Jaroslav Halak’s rocky affair in the Mile High City (19 saves on 25 shots), Cassidy was unimpressed his goaltender couldn’t bail out a frazzled five-pack of Chara-less defenders.

“Your goaltending needs to be a little sharper,” Cassidy said. “That’s just a fact. It was great last weekend. Tonight, he wasn’t on top of his game. We didn’t get away with it.”

On the first night of a back-to-back, it makes sense Cassidy would tab Tuukka Rask, who stepped away last weekend to handle family business. Rask submitted one of his best efforts of this season in the first meeting against the Stars, when he saved 24 of 25 shots.

Halak could go Saturday in Arizona, when the Bruins finish the back-to-back and three-in-four run.

■  David Backes, 13 games into his third season in Boston, cracked the scoresheet by getting a few carbon fibers on a power-play pass Pastrnak deflected home. Backes, riding right wing on Line 4 of late, last scored a regular-season goal April 8 against Florida.

Follow Matt Porter on Twitter at @mattyports