Entering the journey, one that he now hopes leads to full-time employment with the Bruins in 2023-24, Reilly Walsh had the typical teenager’s simplified view of an NHL career arc.

“I always thought it was going to be, ‘OK, you get drafted, you sign, you play … you have a 15-year career, and then you retire,’ ” Walsh mused, the slight chuckle in his voice acknowledging his naivete. “Obviously, that’s not how it works.”

Now 24 years old, with a curriculum vitae that includes three years on the Harvard blue line (2017-20), followed by three more in the American Hockey League, Walsh has lived the more conventional learning curve that can lead to the big time. He was drafted six years ago by the Devils, needed time for his body and game to mature, and last month may have received the break he needs with the trade that added him to the list of Bruins backline prospects.

“It’s a fresh start for Reilly, and you can hear the excitement in his voice,” said his agent, Matt Keator. “Now, obviously, he has to earn his playing time on a good Bruins team. He knows that, but he feels he’s ready to break through after his years in the AHL.”

Walsh was one of three right-shot defensemen that general manager Don Sweeney added to the club’s prospect pool leading up to last month’s draft, depth that could fill the void created by Connor Clifton’s UFA departure to Buffalo. Ian Mitchell and Alec Regula came aboard in the deal that sent Taylor Hall to the Blackhawks, followed by the swap with New Jersey that saw the Bruins send out Shane Bowers for Walsh.

Mitchell, by virtue of the one-way contract he recently inked (guaranteed $775,000), likely will have the edge over the other two going into September’s training camp. Regula and Walsh signed two-way deals, making it easier and cheaper to assign them to AHL Providence.

But of the three, Walsh owns what could be a differentiating skill set, his demonstrated ability to help run a power play and put up points. In his three pro seasons (Binghamton, Utica), he led New Jersey’s AHL affiliate in backline scoring, including a 9-32—41 line last season with the Utica Comets. Across the AHL, only 15 defensemen collected more points.

His time in the AHL, said Walsh, helped him build needed defensive elements into his game, and overall add a pro’s mentality in regard to training, diet, and nutrition. Like most kids, he had to live it to understand what it takes.

“Every kid in hockey dreams of one day playing in the NHL,” he said. “But it only became, you know, a realistic goal for me in the last handful of years. And you realize, ‘Oh, it’s actually way harder than what I had in my head.’ Then you’ve just got to work.

“I definitely didn’t know it was this hard. Playing at Harvard, and before that in the USHL, I mean, the AHL wasn’t even in the [equation] for me, because I had no idea how it all worked. The AHL is an amazing league. It’s hard. It shapes people. It’s a big part of development.”

Born in Framingham, Walsh grew up in Andover, N.H., on the campus of Proctor Academy, where his father, Mike, was the school’s longtime hockey coach. The senior Walsh, who played at Colgate, spent some seven seasons in the AHL, including a 1989-90 season in which he led the Springfield Indians in scoring and to a Calder Cup championship.

Three members of that Indians squad went on to become NHL GMs: Tom Fitzgerald (New Jersey), Kevin Cheveldayoff (Winnipeg), and Marc Bergevin (Montreal). Fitzgerald, who wrapped up his playing career with a season as a Bruin, was the one to sign off on the swap that sent the son of his former Indians teammate to the Bruins. Small world, hockey.

“There was a significant amount of interest in Reilly in the trade market,” noted Keator. “His career path definitely got blocked in New Jersey, when they added [Simon] Nemec and [Luke] Hughes. And to Tom Fitzgerald’s credit, he moved him to give him the opportunity to play up with a different organization.”

Walsh, now finishing the final course to complete his Harvard undergraduate degree in sociology, recently moved to South Boston. In recent days, he has been a frequent visitor to informal workouts at the Bruins practice facility in Brighton, skating with potential varsity teammates such as Brad Marchand, Charlie Coyle, and David Pastrnak, and other Black-and Gold hopefuls such as Johnny Beecher, Marc McLaughlin, and Trevor Kuntar.

During his time in the Devils system, Walsh got to know Pavel Zacha and Jesper Boqvist, both of whom are now Bruins. He also spent time with Jeremy Swayman — a recent golf buddy — in their time trying out for a US world juniors squad.

Come Sept. 20, the start of varsity training camp, he’ll be wearing a new sweater, but he’ll be surrounded by some familiar faces.

“I obviously think I’m going to get a really good chance to make it,” said Walsh. “I’ve just got to go into camp and execute, have fun, and not get too stressed out about it all.

“That’s kind of the biggest thing for me, is that if I just kind of enjoy the process and just have fun with it, I tend to play a lot better. That’s the plan, anyway.

“Obviously, plans don’t always go as expected, but I hope to make it his year — and hopefully never look back.”