Whether it was the firing of Claude Julien, the four-game losing streak in late March or their fight for playoff positioning, the Bruins entered their first postseason appearance in three years having encountered their share of adversity during the 2016-17 regular season.

In an intense playoff atmosphere in Ottawa for Game 1 on Monday night, the Bruins were already faced with injuries to two of their top-four blueliners. Both Torey Krug (lower body) and Brandon Carlo (upper body) missed the B’s first playoff game since May 14, 2014, after suffering their respective injuries in the last two games of the regular season.

It only got worse for Bruce Cassidy and company when David Krejci left warmups due to an upper body injury and was deemed out for Game 1. That forced the Bruins’ coaching staff to juggle up the forward lines, most notably putting David Pastrnak on the first line with Patrice Bergeron and Brad Marchand.

That wasn’t the only time Cassidy’s hand was forced. On a night where Charlie McAvoy made his highly anticipated National Hockey League debut, the Bruins blueline was hit hard again thanks to Mark Borowiecki’s nasty knee on knee collision with Colin Miller. Though Miller did skate a couple of shifts following the Borowiecki incident that saw the Sens defenseman earn a two-minute minor, the second-year Bruin did not return in the third period.

For the third straight game, the Bruins finished the game with five defensemen.

“Losing Colin Miller sort of magnifies the situation,” the Ottawa-born Cassidy told reporters during his postgame press conference. “What is this, the third game in a row that we’ve lost a defenseman? It can wear on you. Especially with a team like Ottawa that puts the puck behind you and makes you go back and get it.”

In addition to the injuries, the Bruins entered the third period trailing 1-0 after Bobby Ryan’s second period tally. During that middle stanza, the Black and Gold looked more like Black and Blue thanks to the injuries and the fact that they fired a grand total of zero shots on goal in those 20 minutes of play.

No matter. Tuukka Rask stood tall all night making timely saves to keep the Bruins in it. McAvoy was nothing short of impressive in his 24-plus minutes of ice time. The Bruins eventually got pucks in deep against Guy Boucher’s famed 1-3-1 system, and it paid off with third period tallies from another playoff newcomer Frank Vatrano (who broke a 16-game goal drought) and Marchand, who was fresh off serving his two-game suspension for spearing Lightning defenseman Jake Dotchin.

Vatrano, Marchand, McAvoy and Rask might have been the saviors, but at a time of desperation, every Bruin on the bench played a key role in overcoming the 1-0 deficit against a Sens team that had the second highest points percentage in the league when scoring first during the regular season.

“I think as a group, we weren’t getting frustrated in one another,” Vatrano said in his postgame interview session with the media about the sloppy second period. “Obviously, when things aren’t going your way, you can kind of point the finger at one another, but we didn’t do that, guys were in here picking each other up.”

“A lot of guys did a good job at stepping up in the third. We used everyone, and that’s what you need to be able to do in the playoffs,” Marchand told the media after scoring his first playoff goal since June 3, 2013 against the Penguins. “You need to be able to use the whole bench and guys did a really good job of coming in and stepping up.”

Every team will face adversity at more than one point in the season. The Bruins are no different and come Game 2 on Saturday afternoon, Cassidy may be forced to make a decision to replace Miller on the blue-line if he is deemed out.

Cassidy and company could get help in Game 2 if Krejci is good to go. At the same time, they will still have to persevere on the blue-line.

At this point, the Bruins are used to playing with what they have and are battling on. That can only benefit them as the best-of-seven series progresses.

“Well, I’ve used the word resiliency a lot and I think it’s become a bit of our middle name,” Cassidy told the press. “We’ve gone through quite a bit – in-game and with some injuries, and we find a way. I think this group has got a lot of character and it starts with the leadership.”