The Killer B's are at it again.

PHILADELPHIA — Center Marc Savard took the next big step in his return to full-time active duty with the Bruins when he re-joined the penalty kill during the Bruins’ 4-1 win over Philadelphia in Game 3 of the Eastern Conference semifinal series.

Of course, that return to the PK wasn’t planned. But with David Krejci joining Marco Sturm among the wounded, head coach Claude Julien had to look for other sources of penalty killing personnel.

“It felt good. I’ve killed before,” said Savard, who was a shorthanded contributor this season and last before he suffered a severe concussion in March. “I knew what I was doing out there and [assistant coach Craig Ramsay] went over it with me a bit between periods. I felt great out there. … It worked out well and I’m ready to step up wherever I have to.”

Savard’s first foray into playoff penalty-killing came at a crucial juncture of the game. With the Bruins up just 2-1, Steve Begin took the first penalty of the game. So not only was Boston lacking Krejci and Sturm, it had now lost one of its best penalty-killers. In stepped Savard and Vladimir Sobotka to aid Blake Wheeler, Patrice Bergeron, Mark Recchi and Daniel Paille to get the job done.

“All of a sudden you’ve got Savvy, Vladi killing penalties. This time of year, that’s what you have to do. And guys are stepping up,” Recchi said. “It was great to see them do it. Again in the third, they had to take some extra minutes on the PK and they did a good job.”

Julien talked about keeping those part-time penalty-killers in the loop in case of emergencies.

“The thing is, when we address our penalty kill, we’ve got those guys in the meetings anyway. They’re part of that meeting, so they’re familiar with what we’re trying to do here,” he said. “And we did that exactly for that reason. Those things happen at times during the season, over the course of a game.”

“I talked about guys wanting to take the challenge that was thrown at them, giving them some extra things to do, and they were I think pretty excited about doing the job.”

After surrendering two power-play goals in Game 1 to the Flyers, the Bruins have killed off eight power plays over the last two games. They seem to have made the necessary adjustments to regain the form that made them 19-for-19 against Buffalo in the first round and third in the league overall in penalty killing in the regular season.

“It’s just typical of the team the whole year,” said Recchi. “[Ramsay] has a great structure and the guys really believe in it. The guys play desperate and it can make a difference.”

Now one win away from the third round, Bergeron doesn’t want his fellow shorthanded specialists to rest on their laurels.

“I think we’ve adjusted, but they keep adjusting to us. We have to make sure we’re sharp and keep adjusting during games because there’s so many good players in there, they read us and they throw some things that we’re not expecting,” he said.

The way Boston has responded, regardless of the personnel, there’s no reason to believe the penalty-killing will slack off anytime soon.