The 28 shifts that followed McAvoy’s first went much better – exceptionally, in fact, considering the circumstances. McAvoy is 19 years old. He had zero NHL experience. He was staring down belligerent monsters like Zack Smith who have beards much thicker than the fuzz sprouting from his plump cheeks.

“My first shift, I was a little bit nervous,” McAvoy said after Wednesday’s 2-1 win. “I hit Nash on the butt on a dump-in. I kind of got back, laughed it off, and said, ‘All right, I got that one out of the way.’ ”

OTTAWA — On his first NHL shift, in Game 1 of the NHL playoffs, no less, Charlie McAvoy thudded the puck off Riley Nash’s backside. It was not optimal placement for a puck-moving defenseman, especially considering the counterattack that McAvoy’s tape-to-rear end pass allowed the Senators to launch.


“I thought he was terrific,” said coach Bruce Cassidy. “Nineteen-year-old kid, comes in, never played a game in the National Hockey League. Had composure, saw the ice, defended well. Got his indoctrination over early when he tried to dump one in, hit our guy, and it came back out. I thought he was pretty good. Stayed out of trouble. And we needed it. We needed it. We were having trouble breaking pucks out. That’s an element of his game he does well. We needed it tonight. Then losing Colin Miller sort of magnifies the situation. If he struggled, we would have been in trouble. It was a nice boost for us.”

McAvoy played 24:11, second-most of any player after Zdeno Chara (25:32). He was on the ice for Brad Marchand’s game-winning goal, holding the blue line at the right point while his down-low mates did their thing. McAvoy attempted four shots, three of which the Senators blocked. McAvoy logged 4:13 of time as the point man on the No. 1 power-play unit.


Over his 29-shift debut, McAvoy showed the skills that convinced the Bruins to draft him 14th overall in 2016. He skated well, saw the ice, leaned into opponents, used his stick to defend, and moved the puck with hard tape-to-tape passes. McAvoy showed why he could become the next coming of P.K. Subban – a smooth, energetic, and boisterous right-shot defenseman who can touch every part of the game.

OTTAWA, ON - APRIL 12: Charlie McAvoy #73 of the Boston Bruins skates in his first shift as he makes his NHL debut against the Ottawa Senators in Game One of the Eastern Conference First Round during the 2017 NHL Stanley Cup Playoffs at Canadian Tire Centre on April 12, 2017 in Ottawa, Ontario, Canada. (Photo by Jana Chytilova/Freestyle Photography/Getty Images) Jana Chytilova/Freestyle Photogrpahy/Getty Images

One element McAvoy already shares with Subban is his joy for the game. Another player who chucked a grenade on his first shift might have hung his head, let doubt creep into his head, and watched the rest of his night go down the toilet.

Instead, McAvoy could not wait for his next shift. He was having too much fun to sulk. This may be McAvoy’s livelihood for the next 20 years, but he could not consider such an experience to qualify as work.

“For me, it just felt like I was out there playing hockey. And that’s what I love to do,” McAvoy said with a smile. “When I’m out there playing with amazing players, great people, great players, it makes it even more fun, playing in front of big buildings, big fans, and with great guys.”

Personality is important. It matters to the Bruins that David Pastrnak is the first player on the ice for practice, flashing a grin with every slap shot he fires. McAvoy has the same kind of approach. He loves to play hockey. When dealing with such enthusiasts, it is one less thing for a coach to worry about.


McAvoy’s go-go attitude is one reason the Bruins picked him up by the scruff of the neck and launched him into the deep end. They believed that even after a mistake, which only took him one shift to commit, McAvoy can release, reload, and raise his hand for his next shift.

“Kind of a whirlwind out there tonight,” McAvoy said. “To play in that first game was kind of a rollercoaster of emotion right there. It’s everything you dream of and that kind of atmosphere. The building was rocking tonight. To try and get a feel for the game, it was an up-and-down game for myself. Lot of learning. But overall, it was just awesome to get out of there with a win.”

Plan A would have had McAvoy in a No. 43 Providence jersey playing against Springfield on Wednesday instead of No. 73 in Black and Gold against Ottawa.

But Plan A began to crumble in Game No. 81 when Torey Krug hobbled off the TD Garden ice. It went off for the rails for good one game later after Alex Ovechkin smacked Brandon Carlo’s head into the glass.

If not for two ill-timed injuries to top-four defensemen, McAvoy would have been baking in Providence, so to speak, not to be placed on an NHL table until he was fully cooked by a deep playoff run in the AHL. The Bruins planned to follow the model set by Zach Werenski, who left the University of Michigan after his sophomore season, helped Columbus’s AHL team win the Calder Cup last year, and reported to the Blue Jackets to become the best rookie defenseman in the league. He helped the Blue Jackets qualify for the playoffs. Columbus has Werenski for two more seasons on entry-level dough before he’s eligible for a raise.


While Plan B was not the Bruins’ preference, they had no other choice. Ottawa is a beatable first-round opponent, the only one of the 16 playoff teams that allowed more goals than it scored (minus-2 differential).

Joe Morrow has not played since Jan. 22. In Providence, Matt Grzelcyk is an offensive defenseman. Rob O’Gara plays a defense-first game. Tommy Cross has 12 goals and 23 assists, but has been a fringe NHL defenseman in previous promotions.

McAvoy is a blend of Krug and Carlo. This year, at BU and for Team USA in the World Junior Championship, McAvoy retrieved pucks, pushed the pace, joined the rush, and pounded rubber. He also smacked opponents in open ice and leaned into them in small-area situations. Even before McAvoy ever played a game for him in Providence, coach Kevin Dean noted the Drew Doughty comparison as an all-around, dynamic, and physical right-shot defenseman.

Even with zero NHL experience, such players can help teams win in the playoffs. General manager Don Sweeney would have preferred three full NHL seasons of entry-level dough.


But if McAvoy can help the Bruins get past Ottawa, Sweeney will peel bills from his own wallet when the defenseman is eligible for a raise in 2019 instead of the following year. Winning in the playoffs would be worth it. So far, McAvoy is doing just fine.

Fluto Shinzawa can be reached at fshinzawa@globe.com. Follow him on Twitter @GlobeFluto.