Part of his resurgence this season came from a growing chemistry with DeBrusk, who scored 27 goals despite missing 14 games because of injuries. Part of it came from centering Marchand and Pastrnak while Bergeron missed 17 games.
But part of it also came from a renewed commitment to maintain his weight, something that had fallen off recently. He felt it might have contributed to some of the injuries he sustained in past seasons, and to just not playing as well as he could, especially as long seasons wound on.
He wanted to continue to keep up, in the faster-paced NHL, and with teammates, some of whom are a decade younger.
"We all know the game is faster, right?" Krejci said. "And guys are smaller than they used to be. They're faster, quicker, so that's the part that I wanted to get better at. … Honestly, I feel good [right now]. I feel like I can skate fast more than other people think.
"I know there's lots of faster players in the League or on this team, but at the same time I hold my ground and that's what's more important. If you're one player your whole career it's going to be hard to all of a sudden leave that and go back and try to be the fastest player. It's not gonna happen. So, I obviously work on my strengths, but at the same time tried to get faster."
DeBrusk thinks it has paid off.
"He's got a little pep in his step," he said. "I know people think I'm fast but he's catching up pretty good this year so far. The pace isn't going down anytime soon and I think he's a special player. The way that he plays, he likes to slow the game down, but at the same time he's been more consistent in that area."
But it hasn't been easy. The right-wing spot with DeBrusk and Krejci has been a revolving door this season, with the Bruins eventually settling on Karson Kuhlman - veteran of 11 regular-season NHL games - to start the postseason. Add in his time with Marchand and Pastrnak and, as Bergeron quipped, "I think he's played with mostly, except me, every forward."
And thrived.
"Everyone's asking what's the biggest thing," DeBrusk said. "I think the biggest thing is just his confidence. I think that he's always had that swagger and that belief and no matter who he plays with, if he's playing his game, it doesn't matter who is with him, he'll produce. I believe that's true."
Whatever the impact, whether it was health or nutrition or luck or confidence, Krejci has had an undeniably strong season for the Bruins. He is an undeniably important player for the Bruins, one who former coach Claude Julien used to say was a barometer for how the team as a whole would perform.
Because as Krejci goes, so go the Bruins. And right now, Boston needs that to help swing the series against Toronto back in its favor.