The right-shot blueliner will become just the ninth Bruin in history to play a postseason game before a regular-season contest, joining Bill Anderson, Wayne Harelson Brown, John Byce, Don Cherry, Guyle Fielder, Guy LaRose, Gordon Wilson, and Chris Winnes.
"Just play," Zdeno Chara, who was paired with McAvoy during Tuesday's practice, said of the advice he can pass on to the youngster. "He's obviously a young, talented player. It's been kind of a speed track for him since he joined Providence and obviously signed with the Bruins.
"But, you don't want to overwhelm players like that with too much information or too much talking. They've just got to play and use their talent and use their hockey sense."
Much like Brandon Carlo has for the majority of his rookie season, McAvoy reaped the invaluable benefits of being paired with Chara - even if it was only for one practice.
"Oh man, I mean, the benefits are endless," said McAvoy. "You get paired up with a guy like that [Tuesday] in practice - the amount of lessons that he has, they're endless. He was giving me little pointers here and there.
"When you play with that kind of experience and that kind of career that he's had, the player that he is, there aren't really words for it. It just helps you out a lot."
While McAvoy skated alongside Chara on Tuesday, Bruins interim head coach Bruce Cassidy confirmed Wednesday that McAvoy would start the game on the right side next to Kevan Miller, though that could change as the game progresses.
"I'm just trying to stay calm and cool and realize that I'm here for a reason," said McAvoy, whose parents will be in attendance. "You don't get here by accident. I need to just embrace where I am right now and play a simple, effective hockey game. I know the guys on this team, from top to bottom, are all phenomenal players and they'll all help me a lot tonight."