The Bruins called up defencemen Tommy Cross and Matt Grzelcyk on an emergency basis ahead of Monday's Game 3 against the Boston Bruins.

The team is dealing with injuries to Adam McQuaid, Torey Krug, Brandon Carlo and Colin Miller along the blueline. Of the four, only Carlo and Miller skated on Sunday but interim head coach Bruce Cassidy did not commit to either rejoining the lineup.

Cross, a second-round pick in 2007, made his NHL debut with the Bruins this season and played in three games. He scored 12 goals and added 23 assists in 74 games with the AHL's Providence Bruins.

Grzelcyk, a third-round pick in 2012, played in two games with the Bruins this season. He scored six goals and added 26 assists in 70 games with the AHL Bruins this season.

Cross was paired with John-Michael Liles in practice Monday, while Grzelcyk skated with Miller.

Bruins defence pairings Monday:

Chara McAvoy
Morrow K. Miller
Liles Cross
Grzelcyk C. Miller

The Bruins could receive relief at forward in Game 3, as both David Krejci and Noel Acciari took line rushes during the morning skate.

Krejci will take warmups Monday night, but is still considered a game-time decision. Acciari will play Monday as he returns from an upper-body injury.

The veteran centre has missed both games in the series so far with an upper-body injury. 

The Bruins used the following lines at Monday's morning skate:

Marchand—Bergeron—Pastrnak
Stafford—Krejci—Backes
Schaller—Spooner/Kuraly—Vatrano
Moore—Nash—Acciari

Below is the preview for Monday's Game 3:

The Ottawa Senators-Boston Bruins first-round playoff series might just come down to which team has the healthiest and fully functioning defensemen.

The best-of-seven Eastern Conference series, tied at one game apiece, resumes Monday night at TD Garden. The Senators won on each of their past three visits to Boston, two of them this season.

Ottawa, down 3-1 and on the verge of losing two games at home, rallied for two goals in 2:20 in the third period Saturday and then won it 4-3 on Dion Phaneuf's early overtime goal.

The winning goal went in just after weary Bruins defenseman Zdeno Chara was guilty of a delay-of-game penalty in the closing seconds of regulation - and Ottawa scored just as he was stepping back onto the ice.

The 40-year-old Chara was again overworked because, for the fourth straight game, the Bruins lost a defenseman during the game. This time it was Adam McQuaid, gone with an upper-body injury.

"It's kind of unfortunate but those things happen," Chara said after the game. "You wish that you had a full lineup every game, but it's unfortunate for us the last three or four games we're always losing a body. For the most part I thought we handled it well."

McQuaid joined Torey Krug, Brandon Carlo and Colin Miller in picking up an injury, leaving the Boston defense reduced to five. No sign of when any of the four will be back, although Carlo and Miller both skated Sunday and are considered day to day.

Is Carlo close?

"Going forward is more of a target date," Bruins interim coach Bruce Cassidy said. "That's kind of the way we're looking at it."

The Senators came into the playoffs wondering about Erik Karlsson's foot injury and Marc Methot's finger, which was almost severed at the tip by a Sidney Crosby slash. Karlsson sat out the last two games of the regular season, though the Sens got Cody Ceci back from injury.

Karlsson and Methot are playing in the playoffs. Karlsson looked as special as ever when he set up Derick Brassard for the tying goal Saturday -- and Methot in obvious pain but playing through with plenty of wincing. On Saturday, Mark Borowiecki went down with a lower-body injury.

Borowiecki, who sustained an apparent leg injury, could have returned Saturday but was held out. The Sens skated in Boston on Sunday, coach Guy Boucher saying "we'll see" on Borowiecki's status.

"We've got numbers now and guys that can take over," Boucher told the Ottawa Sun. "We've got all our depth, and everybody else is healthy, so, if we need to use it, there'll be no need to wait, we'll do it for sure."

Karlsson logged 31:29 on 36 shifts Saturday, while Chara played 30:09 on 34 shifts -- a lot of work for an aging warrior.

"Yeah, Zee had a lot of minutes tonight," said Cassidy. "He's a well-conditioned guy and I'm using him as an example, but Charlie (McAvoy, playing his first NHL games in this series) played a lot of minutes.

"On the positive side, Joe Morrow got thrown in there and did a nice job for us. He stepped in and did his job. It's just hockey. They lost a guy too so it happens. We're on a bad run. Let's face it. That's the fourth game in a row where we've lost a guy early."

The Bruins could get right winger Noel Acciari, who brings toughness to their game, back for Game 3.

Karlsson, the Ottawa captain, was disappointed with the way his team played when the Bruins scored three times in the second period. But then came the bounce-back, and the first playoff overtime goal of Phaneuf's career.

"That's the way that we're going to have to play if we're going to beat these guys," Karlsson said. "They're not going to give up. They're a good team even if though they're battling some injuries. It was definitely nice that we responded the way that we did."