ANAHEIM, Calif. — Even with a healthy lineup, the margin of error in the National Hockey League is thin. One mistake and a team is chasing. Even if they respond after giving up a goal or two, they can still find themselves behind the proverbial 8-ball.

For the injury-plagued Boston Bruins, that margin of error is even thinner.

Case in point, Wednesday’s 4-2 loss to the equally banged up Anaheim Ducks in their first of a four-game road trip.

Patchwork lineups weren’t as much of a problem in this one. Even without the likes of Brad Marchand, David Krejci, Anders Bjork, David Backes or Ryan Spooner up front, the Bruins had their chances; most notably in the second period where they outshot the Ducks 15-3.

Only one of those 15 second period shots, however, found the back of the net. That credit went to Danton Heinen who found his way to the slot and patiently fired a backhander past Gibson for the 1-1 equalizer at 8:38.

As the momentum continued, the Bruins were getting more chances on Gibson (39 saves) and appeared to have an extra pep in their step. But then the defensive mistakes came back to haunt them, again.

From Zdeno Chara deflecting a Josh Manson shot for the go-ahead goal to Nick Ritchie getting space in front of Tuukka Rask, the Bruins relinquished whatever momentum they had left in a span of 4:49 – all coming late in the second period.

Corey Perry and Derek Grant combined for the dagger early in the third on another Bruins miscue. With Kevan Miller in possession of the puck, Perry pickpocketed the former Vermont Catamount and assisted on Grant’s tip-in for the 4-1 Anaheim advantage.

“Some bounces were going their way. I thought we had a really good second overall,” DeBrusk said about the middle stanza. “We had some guys in front of the net doing their thing. There were a couple plays there that they capitalized on. It was a lead we couldn’t get back.”

It was a lead that the Ducks held on to without the likes of Ryan Getzlaf, Ryan Kesler and Cam Fowler to name a few.

And, it was a lead the Bruins couldn’t overcome without Brad Marchand, Anders Bjork, David Krejci, David Backes, Ryan Spooner and Adam McQuaid.

Even with the patchwork lineup, Bruce Cassidy knows that it’s a work in progress with the youngsters like DeBrusk and Heinen trying to get acclimated to the rest of the roster. Instead, he drew his attention to the veterans – particularly the goaltending and blue-line.

“Listen, I’m not going to use that as an excuse. We’ve got some young players up front, we know that. But at the back end and our goaltending, there’s experience there,” Cassidy said.

“Other than Charlie [McAvoy], these guys have played in the league, and they’re going to need to carry this team a little bit until we find our scoring and until these young guys get comfortable playing on the road. It was a bit of an issue tonight, and guys are going to have to take ownership of that. We’ve got some leaders back there and I hope that they take it to heart, because we had to be better back there. Sometimes you have to win 2-1, and like I said, that part is experience.”

Cassidy’s No. 1 goaltender, who has given up at least three goals in five straight games, agrees.

“It’s very thin,” Rask said about the margin of error. “We haven’t been scoring a lot lately and those goals have been hard to come by. So, we can’t afford to have any unlucky bounces against and today we had a couple. We have to try to limit our errors and play as solid as possible.”

Another night proving that there’s little room for error for the Black and Gold, who are now 6-7-4 in 2017-18. That same philosophy holds true if Cassidy and his coaching staff ever get a clean bill of health to work with.