BOSTON -- The matter would seem to be settled. Behind Zdeno Chara on the left side of the Boston Bruins defense are Torey Krug and Matt Grzelcyk. Krug has scored at least 50 points in each of the past two seasons (51 and 59), and Grzelcyk is a player in the same mold, who solidified a spot this season with 15 points (three goals, 12 assists) in 61 games.
But each is 5-foot-9 and more known for offensive prowess than stout defensive play, a fact that became problematic in the Eastern Conference Second Round of the Stanley Cup Playoffs when the Bruins -- short second-pairing defenseman Brandon Carlo because of an ankle injury -- lost to the Tampa Bay Lightning in five games.
The likeliest scenario has the Bruins keeping their left side as is, with Chara, Krug, and Grzelcyk. But there are other possibilities, including a trade of Krug, a notion that has been floating around the NHL this summer, though Bruins general manager Don Sweeney said he was not actively shopping Krug and that a trade of him was unlikely.
"Can we continue to get deeper in our overall D-man pool? Probably," Sweeney said recently. "You hope they continue to expect some growth on Charlie [McAvoy], on Brandon, certainly [Grzelcyk], who is 60 games into a career and really did a good job for us. So I think we feel comfortable with the group of seven that we have."
Which brings us to Urho Vaakanainen, Jakub Zboril and Jeremy Lauzon, three left-shot defenseman prospects in the Bruins system, players the Bruins will be tracking closely this summer and into training camp.
"Moving forward … I think we have to be cognizant that we need to continue to groom people that will step into some very significant roles and minutes and that's where Urho and Zboril and Lauzon and all the guys that are part of our development process need to feel like there's an opportunity there," Sweeney said. "And if they can grow and take it, then we're in better shape. If they can't, then we probably have to go and acquire it."
And that would be a disappointment after spending two first-round picks and a second-round pick on the trio.
Of the three, the 19-year-old Vaakanainen, the No. 18 selection by the Bruins in the 2017 NHL Draft, is the only one attending development camp at Warrior Ice Arena this week.
Video: Urho Vaakanainen speaks with Steve Mears
"My goal is just to get the spot from Boston Bruins," said Vaakanainen, who signed a three-year, entry-level contract with an average annual value of $925,000 on June 13. "I think if I do well I have a chance and I think they're going to let the young guys show their talent and give them a chance. So you never know. But my goal is to take the spot from Boston."
During Sweeney's tenure, he has shown a willingness to let the players dictate their readiness, inserting half a dozen rookies last season for at least 30 games (forwards Danton Heinen, Jake DeBrusk, Sean Kuraly and Anders Bjork, plus McAvoy and Grzelcyk). Which might make him leery of inserting yet another, especially with rookies Ryan Donato and Peter Cehlarik possibilities on offense.
But that doesn't mean players like Vaakanainen, Zboril and Lauzon won't get a long look, especially with the Bruins needing to field two squads for half of training camp, with one group off to play two preseason games against the Calgary Flames in China and one left behind at home.
Zboril was selected No. 13 in the 2015 NHL Draft, the first of three consecutive picks for the Bruins. The 21-year-old had 19 points (four goals, 15 assists) in 68 games this season with Providence of the American Hockey League. Lauzon, also 21, was a second-round pick (No. 52) in that draft. He was a teammate of Zboril's in Providence, with seven points (one goal, six assists) in 52 games.
"I think with where they were drafted, their potential is as top-four guys," Bruins director of player development Jamie Langenbrunner said. "That's where they are projected to be. When they'll get there, nobody knows. We're not in a rush. We're worried about just building them along and they'll get there when it's their time."
Video: Billy Jaffe on the Bruins' offseason plans
In the meantime, it's the job of Sweeney and Langenbrunner and the Bruins to manage their expectations and to aid their development and, if they're ready, to spot that readiness.
"I think that sometimes when you feel like it, you look at a roster and you go, 'Well, where's the job for me?'" Langenbrunner said. "Letting them know that there is a plan if they continue to progress to have that opportunity. I think we've proven that in the way our lineup has shifted the last few years with a lot of young players getting a chance."
For Vaakanainen, who played last season for SaiPa of Liiga, Finland's top pro league, this has been a year of development. He spent training camp with Finland ahead of the IIHF World Championship and though he did not earn a spot, he believes it was crucial in his push to make the jump to North America, either with the Bruins or with Providence.
"I had a great four weeks with the men's national team after the season, gave me a lot of confidence playing against a lot of NHL guys," Vaakanainen said. "Without those games, I wouldn't be as confident as I am right now. But right now I feel really confident, that I can do the jump."
That is exactly the hope.
"We really think it's time for him to take the next step," Sweeney said. "We're excited. He's a great-skating mobile defenseman, puck mover. Offensive blueline is an area where we want to continue to see him grow and get more confident to spread his wings in that area. And we're going to give him the right opportunity, so we're excited to have him."
They will all get that opportunity. They will all get the chance to prove they belong. And even with his established players, even with a seemingly settled left side of his defense, Sweeney would be glad to see them take advantage.
If Vaakanainen can do it -- or Zboril or Lauzon -- it would be the best kind of problem to have.