The Washington Capitals aren’t happy. In fact, they’re downright ticked off at the NHL’s decision to suspend forward Nicklas Backstrom for one game while the Boston Bruins remain unpunished for any of their indiscretions — real or perceived.

The Bruins, for their part, have taken exception to the headhunting accusations the Capitals’ coach and players have made in the 48 hours since the teams last played a game.

It’s with this backdrop of verbal jousting and lobbed insults that the Capitals and Bruins will meet for a pivotal Game 4 in their Eastern Conference quarterfinal series Thursday at Verizon Center. Boston leads the series, 2-1 and, with Backstrom out of the lineup, the Capitals must try to even the series without their best playmaker.

“We disagree with the NHL’s decision to suspend Nicklas Backstrom,” the Capitals said in a statement released by the front office. “This has been a competitive and physical series, and we do not understand why a suspension was imposed in this case while other incidents in this series have not been reviewed. Our singular focus now is on Game 4, and we look forward to the energy that our great fans provide.”

Washington’s frustration at losing Backstrom is understandable. While the team grew accustomed to playing without the Swedish center during the regular season, when he missed 40 games with a concussion, Backstrom’s absence weakens the Capitals’ overall depth and removes their most well-rounded player.

Backstrom expressed regret for the cross-check to Boston forward Rich Peverley’s head as time ran out in Game 3 that resulted in the suspension. “I did what I had to do,” Backstrom said. “I think it was stupid on my part. I’ve got to deal with it now.”

While the Capitals talked about standing their ground and not being baited into retaliating against the Bruins on Thursday night, Boston Coach Claude Julien took exception to Capitals Coach Dale Hunter’s claim that the Bruins were targeting Backstrom’s head.

“It’s ludicrous. It’s ridiculous,” Julien said. “I don’t blame Dale for defending his player, if that’s what he’s trying to do. To me, it’s going to war for your team, and I’m not commenting more on that. I’m not gonna comment on his comments on protecting his player, if that’s the case. But if he really believes the other way around, that’s the part that I don’t [understand]. Being accused of headhunting is ludicrous.”

Asked about the accusations from Hunter, the Bruins shrugged off the notion they would intentionally try to injure a player with a history of head injuries, considering that several of their teammates, including Marc Savard, Nathan Horton and Patrice Bergeron, suffered or are still coping with concussions.

“Obviously [Hunter] is saying stuff to protect his players and that’s about it. For us, our main focus isn’t about what’s being said in the paper or anything like that,” forward Milan Lucic said. “We just worry about ourselves and what’s in this dressing room and I think that comes from our past experiences and how we’ve dealt with situations in the past.”

The absence of Backstrom will force the Capitals to alter their lineup and place several players in different roles. Mathieu Perreault, in his first full season in the NHL, will shift back to the second-line center spot with more pressure to produce offensively between linemates Jason Chimera and Alexander Semin.

Veteran winger Mike Knuble is expected to round out the forward corps after being scratched from the lineup for four games.

It will also force tweaks on special teams, particularly on the power play where Backstrom serves as the quarterback. Although the Capitals have tried other players in that role, none has the same passing skill.

Washington went 18-16-6 without Backstrom in the regular season.

“Nicky is the guy that makes this team tick,” defenseman Karl Alzner said. “We’ve all seen the differences with him in and out of the lineup. It’s too bad. It changes the dynamic of a lot of the things we do, but it’s still going to be just a basic game from us. We’re not going to try to change too much.”

The Capitals likely will try to get back to a simple, defensive style they executed well in Games 1 and 2 in Boston. Part of accomplishing that goal, though, includes avoiding any altercations after whistles.

In their victory in Game 3, the Bruins appeared to gain traction as they agitated the Capitals, whether by knocking down players waiting for a faceoff, inciting battles after a play concluded or drawing penalties such as Backstrom’s cross-check.

Washington took nine penalties in the contest; Boston took seven.

Capitals owner Ted Leonsis took to his blog Wednesday to urge his team to maintain its discipline.

He also took a shot at what he said was an officiating bias in the series.

“We can’t let the officials play a role in our game planning,” Leonsis wrote. “We need to remain disciplined and remember that the defending Stanley Cup champs will always get the benefit of the doubt; we need to rise above the noise and focus on signal; play tight defense — capitalize on Boston’s mistakes — score when we get a power play; continue to rely on strong play in net. Don’t retaliate to plays after the whistle.”