Dennis Seidenberg is back in the Bruins’ lineup for Game 5 of the Eastern Conference semifinals after being out since the first period of Game 7 of the first round with a lower-body injury.

With Seidenberg back, Dougie Hamilton is out. Seidenberg was paired with Zdeno Chara in warmups, while the other pairings were Matt Bartkowski-Johnny Boychuk and Torey Krug-Adam McQuaid.

Bruins coach Claude Julien said Saturday afternoon that Dennis Seidenberg will dress for warmups prior to Game 5 of the Eastern Conference semifinals against the Rangers. The team will decide after the warmup whether Seidenberg will then play in the game.

Seidenberg has not played since Game 7 of the first round against the Maple Leafs, as he suffered a lower-body injury on his first shift and skated only one more shift in the contest.

If Seidenberg is to play, Dougie Hamilton would be the most likely player to come out of the lineup.

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Tuukka Rask and the Bruins know they let one get away after Rangers forward Chris Kreider scored in overtime to end Game 4. (AP)

The Bruins suffered what had to be their ugliest loss of the playoffs Thursday at Madison Square Garden, as they blew two separate leads in the third period and instead of sweeping the Rangers suffered their first loss of the series. Chris Kreider scored in overtime to give New York a 4-3 win.

The Bruins took a 2-0 lead in the second period on goals from Nathan Horton and Torey Krug, but Carl Hagelin brought the Rangers within one on a shaky goal in which Tuukka Rask fell down. Derek Stepan tied it in the third period after taking the puck away from Zdeno Chara rather easily, and although the Bruins took the lead yet again on Tyler Seguin‘s first goal of the postseason, New York tied it again on a power-play goal from Brian Boyle.

The series will return to TD Garden for Saturday’s Game 5, with Game 6 taking place in New York if necessary.

WHAT WENT WRONG FOR THE BRUINS

- A too-many-men penalty right after regaining the lead in the third period of a closeout game? Win or lose, this game was going to be one of their more discouraging efforts of the season. To blow two different leads in the third period of a closeout game and take bad penalties in the process speaks to lack of focus. That was pretty apparent from the Bruins in the third period.

– The Rangers got away with one in the second period when Derick Brassard was the only one to drop his gloves. Brassard put both gloves on the ice in an attempt to get Brad Marchand to fight, but Marchand didn’t oblige. It should have been a penalty on just Brassard, but nothing was called.

– For as solid as Rask had been in this series, Game 4 was easily his worst performance. Holy moly, was that Hagelin goal a bad one. It seemed like Rask simply lost his balance and fell down as he was trying to adjust with Hagelin and Johnny Boychuk drawing nearer. Until that point, Rask had only seen six shots on goal, so perhaps that helps explain the shakiness of the play.

The goal also gave the Rangers new life, as the energy both on the ice and in the stands was perilously low following Krug’s goal, but Hagelin’s tally led to some lengthier trips to offensive zone for the Rangers.

– The Bruins might want to work on their drop passes, or at least read up on to when it’s practical to do them (like when a player on your team is behind you). Two drop passes led to turnovers Thursday night, with Adam McQuaid the culprit in the first period and Rich Peverley making the error in the third.

WHAT WENT RIGHT FOR THE BRUINS

– That’s now three goals in four games for Krug. Maybe now he has moved ahead of Matt Bartkowski in the pecking order for which youngsters stay un when the B’s get their injured defensemen back.

– In what’s been a rather dreadful postseason for Seguin, he had easily his most productive night of the playoffs with his third-period goal and the primary helper on Krug’s tally.

NEW YORK — Speaking of super weird tweets, Marc Savard thinks John Tortorella should get fired:

Tortorella should get fired right after the game he has ruined all of his players confidence #Richardswillget80pointsnextyear #ByeByeTorts

— marc savard (@MSavvy91) May 23, 2013

The tweet came in response to Tortorella’s decision to make Brad Richards a healthy scratch for Game 4 against the Bruins. This would technically qualify as trash talk, as Savard is still under contract with the Bruins through 2017, though his career is effectively over due to concussions.

For more on the Bruins, visit weei.com/bruins.

Brad Richards will be a healthy scratch Thursday. (AP)

NEW YORK — So Brad Richards won’t be in the lineup in Game 4 of the Eastern Conference semifinals. That’s pretty big news purely from a standpoint of how far he’s fallen. As it pertains to this series, it isn’t really that big a deal unless the guy who plays in his place (Kris Newbury and Michael Haley are the candidates; fellow fourth-liner Arron Asham is a potential scratch as well) has a big performance.

John Tortorella was playing Richards on the fourth line. Richards played only 8:10 in Game 3, so although he’s a big name with a big contract (his nine-year, $60 million deal of which he’s in the second year screams amnesty buyout), it isn’t like the Rangers are taking one of their top-six forwards out of the lineup.

So when the Bruins, who were on the ice for their morning skate when Richards said he wasn’t playing in Game 4, found out about the development, they didn’t begin to think about all the questions that will accompany it (Has Richards played his last game as a Ranger? Will Tortorella get fired?).

“Obviously they’re going to make changes, but that’s their job,” Chris Kelly said. “Our job is to focus on our team and be ready to play right from the drop of the puck and be ready to play a good road game.”

Daniel Paille sees the move as something that will give the Rangers a greater focus in Game 4 as the team tries to stave off elimination.

“I think whoever’s going to take his spot is going to want to be a difference-maker, and it’s just going to make it that much harder,” he said. “I think that will wake up their team and [help them] realize that they have to play hard.”

The Bruins are clearly focused more on their lineup than New York’s. The B’s are expected to go with the same group they’ve used in the first three games of the series, as Dennis Seidenberg and Wade Redden still aren’t expected to jump back in.

As for Richards’ take, he was a man of few words Thursday morning. He admitted that it was difficult to be productive on the fourth line, but that the development is all the motivation he needs for him to never let it happen again.

Richards won’t be the only new absence to the Rangers’ lineup. While Asham did not confirm that he is out, defensemen Anton Stralman was hurt in Game 3 and is expected to be replaced by Roman Hamrlik.

Brad Richards

NEW YORK — With the Rangers on the brink of elimination, John Tortorella is sitting embattled center Brad Richards, the slumping scorer revealed Thursday after staying out on the ice following the team’s morning skate.

Richards, who is earning $12 million this season in the second year of his nine-year, $60 million deal (carrying a cap hit of $6.66 million), has skated on the fourth line in the first three games of the conference semifinals against the Bruins. He has no goals this postseason after scoring 11 in the regular season.

Richards said Tortorella called him Thursday morning to tell him he would not be playing.

Brad Marchand and the Bruins have jumped out to a 3-0 series lead over the Rangers. (AP)

NEW YORK — With the Bruins a win away from the Eastern Conference finals, they hope to have a better focus than they did the last time they got their third win. The B’s let the Maple Leafs come back from a 3-1 deficit last round to nearly eliminate them, so they weren’t getting too far ahead of themselves after their 2-1 Game 3 win.

“We’ve had the experience, but we’ve also had a tough time closing out teams and we know they’re going to be tough to play against in Game 4,” Shawn Thornton said. “Their backs are against the wall, so that’s usually when you see the most desperate of teams. I think we’re going to have to be ready for that again.”

Though the Bruins have a 3-0 series lead, Games 1 and 3 could have gone either way. If a few bounces went the Rangers’ way, this series could be much closer, and the B’s aren’t forgetting it.

“Every game is a tough game,” Zdeno Chara said. “Sometimes the scores aren’t always showing how close the games are.”

Game 4 will be played Thursday at Madison Square Garden.

“We know it’s going to be a tough one,” Patrice Bergeron said. “It’s always a tough win to get, is the last one. We have one day to regroup and we need to make sure we’re ready for Game 4. We know the Rangers are a team that’s not going to give up, so it’s about making sure we’re ready for that game.”

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