Over the course of Development Camp, Langenbrunner - who had seen Vaakanainen play just once, during the 2017 World Juniors - also had the chance to get a better look at the defenseman's game.
"He's a smooth skater. He sees the ice well, he's got good size, and he can make plays," said Langenbrunner. "I think as the confidence grows, numbers will grow just if you're making the right plays over and over again."
Langenbrunner said the graceful nature of Vaakanainen's skating reminds him and Bruins assistant general manager Scott Bradley of Hall of Famer Scott Niedermayer, who was teammates with Langenbrunner on the New Jersey Devils 2003 Stanley Cup squad.
"Fluid, where you're almost floating on the ice," said Langenbrunner. "You're not exerting effort to get to the same place where it's just - it's effortless where you think a guy like that can play 50 minutes in a game and not get tired, which I believe Niedermayer probably could of.
"That's obviously high praise with a guy that is effortless and can skate around the rink…that's something that I don't believe you can really teach. Some guys have that and some guys, it's a little more work."
High praise, indeed, for an 18-year-old.
But there is still plenty of progress to be made, particularly in Vaakanainen's offensive game. While the 6-foot, 185-pound left shot can certainly lug the puck with his legs, it has not always translated into gaudy numbers on the scoresheet.
Last season, Vaakanainen collected two goals and four assists in 41 games for JYP, while adding another three assists in 14 postseason games. Langenbrunner, however, believes the numbers will come with time.
"You're talking about a 17-year-old kid that played in the Finnish Elite League," said Langenbrunner. "So, for him to put up huge offensive numbers, I think would be pretty tough. I think now, going into his second year there, a little more confident. Obviously, you hear more growth. You'll see maybe a little more of an uptick there."
Vaakanainen, who will play in Finland again next season, tried to gather as much as he could from the four-day camp, most importantly what it's like to be a member of the Boston Bruins organization.
"As the camp goes, you feel more welcome and more relaxed," said Vaakanainen. "The camp was great. I had so much fun here. Tried to learn some new things, get to know all the guys. I really liked the people here in Boston and the Bruins organization. I really enjoyed my time here."
The 2017 Boston Bruins Development Camp was presented by AT&T.