The shock only grew after the 2-1 double overtime win by the Bruins against the Pittsburgh Penguins in Game 3 of the Eastern Conference Final when news filtered out that Campbell had a broken leg, a report the Bruins confirmed to be a fractured fibula Thursday morning.
But the people who know Campbell best weren't shocked in the least.
"That's the kind of player he is," Bruins coach Claude Julien said Thursday. "He's a real dedicated individual to his work and to his game, from off ice, to on ice, to taking care of himself, demeanor, everything else. What he did [Wednesday] surprised a lot of people, but it didn't surprise us because that's just who he is."
The Game 3 victory gave the Bruins a commanding 3-0 lead in the best-of-7 series, with Game 4 Friday at TD Garden (8 p.m. ET; NBCSN, CBC, RDS).
Campbell's injury happened when he laid down in front of an Evgeni Malkin slap shot just after the 12-minute mark of the second period while killing a Boston too many men on the ice penalty. Campbell struggled to get back on his skates and remained on the ice, disrupting the Penguins' power play just enough to help keep it from scoring and limping back to the Boston bench under his own power nearly a minute after the injury.
It was an inspiring moment that charged up the TD Garden crowd and gave his teammates a lift at a time in the game where the Bruins weren't playing their best hockey.
Now they want to make sure Campbell's efforts weren't for nothing.
"We talked about it and we don't want that to go to waste," Campbell's linemate Shawn Thornton said. "It takes a big set to lay down in front of a slapper like that, and obviously you saw him play on a broken leg for 45 seconds. You want to play well for him after that, that's for sure."
Campbell's injury cannot simply be written off as the loss of a fourth-line center because he represents a big part of the Bruins' identity and why they are such a difficult opponent.
Campbell is the anchor of Boston's fourth line with Daniel Paille and Thornton, the so-called "Merlot Line" because of the color of their jerseys during Bruins practices. The effectiveness of that line is what allows Julien to roll all his lines over the course of a game, wearing down opponents by maintaining a high level of energy across the board. That in turn allows each of Boston's forwards to effectively employ Julien's forechecking scheme, which can be quite aggressive when playing from behind or can become more of a passive style when protecting a lead.
Without Campbell for the remainder of the Stanley Cup Playoffs, Julien will need to find a combination that allows him to maintain that four-line attack.
"We've just got to make sure we get something out of all of our lines right now," Julien said. "I think that's the most important thing for us, and that's where decisions are going to have to be made and how do we make it work so that we continue to have four lines."
Julien was not tipping his hand as to which forward will be entering the lineup Friday night, only saying he has "lots of options." Among those options would be veteran Jay Pandolfo, who has 131 games of playoff experience; Kaspars Daugavins, who played in the Bruins' first playoff game this season; Carl Soderberg, a Swedish rookie who played in six games toward the end of the regular season; and big-bodied Jordan Caron.
None of those players are centers, though Soderberg is listed as one, but Julien has the luxury of having Rich Peverley, a natural center who is strong on faceoffs, playing at left wing on his third line. A likely scenario could have Perverley moving to center the fourth line while whoever draws into the lineup fills Peverley's spot on the third line with Chris Kelly and Tyler Seguin.
As far as Thornton is concerned, whoever is chosen should be able to make a seamless transition into the lineup.
"Myself, [Paille] and [Campbell] have been playing together for a while and we read off each other very well without needing much communication," Thornton said. "If me and [Paille] still happen to be together, whoever's in between us, it won't be that much of an adjustment. We're pretty straight-line hockey players, so it should be easy."
SOG: 20 | +/-: 7
If Julien chooses to go with Daugavins or Pandolfo, each has experience killing penalties and could take some of Campbell's minutes there.
However, they likely will not be able to replace Campbell's offense, with three goals and four assists in 15 games, tying him with future Hall of Fame member Jaromir Jagr for seventh on the Bruins in scoring.
Whoever is chosen to replace Campbell will have to be ready after spending a month skating as part of the Bruins' taxi squad.
"When you're not playing, you always want to stay ready because you never know when that opportunity's going to come," Pandolfo said. "You start in the first round and second round with us having three [defensemen] go down, so there's always that chance you'll get in there. You always want to stay sharp in practice and do the best you can to stay in shape. That's what we've done."
Campbell's absence will surely be felt on the ice and his disappointment in not being able to continue is obviously considerable. But the Bruins will still be counting on his presence off the ice for inspiration and leadership as they seek to close out a surprising sweep of the Penguins in Game 4 on Friday.
"I'm not sure if I've ever played with anyone who spends that much time at the rink," Thornton said of Campbell. "He loves it. He grew up with it. I'm sure he's a little down in the dumps, but he'll be positive when he's around the guys and help out any way he can off the ice, I'm sure.
"He's still a big part of this team, whether he's on skates or not."