The Pittsburgh Penguins talk a lot about turning the page from one game to the next, but they also have had several outings that sting enough to linger.

They are at the latter point going into a game Friday against Boston (17-10-4).

Pittsburgh (13-11-6) had points in four straight games before falling 6-3 on Wednesday at Chicago, which entered the game last in the NHL with nine wins and riding an eight-game losing streak, and played the night before.

"To not have the fire or whatever, the jump, I don't know if there's an excuse for that," Penguins forward Matt Cullen said after returning for that game from a lower-body injury.

Pittsburgh had some feel-good moments in the game, erasing an early two-goal deficit and getting a hat trick from Bryan Rust, who busted a 20-game goal drought.

But for what is far from the first time this season, the Penguins find themselves fighting the frustration of some deficiencies that keep cropping up -- defensive lapses, critical penalties, poor puck management and a lack of an offensive response at key times.

It's not all of those things all the time, but it's enough of them enough of the time to be concerning to them.

"We're trying to build some traction here," Pittsburgh coach Mike Sullivan said. "We've played a lot of good hockey over the last three or four weeks. We're trying to string some wins together and points together and (produce) momentum. When you have a night like (Wednesday), it sets you back.

"I thought we gave up more odd-man rushes than we did in the last three or four weeks."

Pittsburgh goaltender Matt Murray (lower body) came off injured reserve Wednesday and dressed as the backup to Casey DeSmith. It's not clear who will start against the Bruins.

Boston has won three straight.

Bruins center Ryan Donato has never faced Pittsburgh, and his impression of the club that has won three Stanley Cups since 2009 remains strong.

"It's one of those talented NHL teams that capitalize on every mistake," Donato said. "I look up and down their lineup and they have a lot of superstars, so I think for us we've got to come in with a mentality of being really hungry and prepared to play some defense, but also not make any mistakes."

Boston is moving toward being healthier.

While winger Jake DeBrusk has gone into concussion protocol and will sit out Friday, winger David Backes has had no lingering effects from being cut in the face Tuesday and is expected to play Friday.

Backes took a skate to the face during a 4-3 win over Arizona. He returned to the game after receiving stitches.

"No worse for wear," Backes said Thursday. "It could have been a lot worse looking at the video and knowing that there's some sharp apparatus right by my moneymaker, my face."

Center Sean Kuraly did not practice after having a minor procedure on his broken nose, the result of a fight Sunday against Ottawa's Ben Harpur. Coach Bruce Cassidy said Kuraly was questionable to probable to face Pittsburgh and might need to add some extra facial protection.

Meanwhile, center Patrice Bergeron (rib, sternoclavicular injury) and defenseman Zdeno Chara (left MCL injury) skated before practice, and defenseman Kevan Miller (throat) practiced in a limited capacity.

"He's practicing in a non-contact jersey, so he's able to do that, so that's good," Cassidy said of Miller. "He'll obviously have to get cleared for contact."