The star winger, whose scoring prowess is equaled by his abilities as an agitator, told the media on the team's breakdown day that he intends to change his act.
"The biggest thing for me is taking a pretty hard look in the mirror and realize that some of the things I'm doing have much bigger consequences," he said on Wednesday. "The last thing I ever want to do is bring embarrassment to my teammates and the organization like I did."
During the Bruins' five-game defeat to the Tampa Bay Lightning in the Eastern Conference semifinals, Marchand was told by the NHL to stop licking the faces of his opponents in an effort to instigate them, something he had done against the Lightning's Ryan Callahan and Leo Komarov of the Toronto Maple Leafs earlier in the 2018 Stanley Cup playoffs.
"There is absolutely no place in our game for that," Lightning coach Jon Cooper said after the second incident. "I don't get it. I don't understand it. I don't. How would you feel if I walked over to your right now and gave you one big lick from the chin up?"
Marchand, who turns 30 on Friday, said it'll be an offseason of self-evaluation for him as a player who competes on the edge of legality.
"There's a difference between having an edge and being stupid," he said. "That's where I get into trouble. That split-second reaction. I'm at that point now where, if you look at the last few years, if I have to cut off that edge and maybe drop 15 or 20 points, maybe that's worth it. I don't have the answers right now.
"It may not happen in six months. It may happen in a year or year and a half. But I if I can turn it around for the second half of my contract, maybe it's worth it."
"That's something I've wanted to work on for the last few years, to move more into that role," he said. "I gotta figure some s--- out before that's really going to happen. To get to that next level. I gotta get rid of that stuff."
Marchand acknowledged that there's a novelty and an effectiveness to being the player he is, and that in the past, his antics might not have received the same level of scrutiny and were allowed to continue.
"When you play a certain way with no consequences for 25 years, it's hard to flip a switch and have it all be gone. Maybe I haven't paid enough attention to it, because I thought I could get away with it because I was being a good player," he said. "If I wasn't having the years that I was having, would I be in the league? I don't know. Would the Bruins put up with it? Probably not."
Marchand is demonstrably a good player. Since 2015, only Alex Ovechkin (132) and Vladimir Tarasenko (112) have scored more regular-season goals than Marchand (110), and he has the sixth-best points-per-game average in that span (1.03).
"I've gotten my game to a pretty decent point," Marchand said, "but I have some character things, and things that I've done, that need some fixing."