BOSTON (CBS) — In one brief response to a question about 2014 first-round draft pick David Pastrnak on Friday, Bruins general manager Peter Chiarelli simultaneously tamped down enthusiasm for the Czech Republic native making the NHL roster as an 18-year-old and left open the door that Pastrnak will both be with the team and among the top-six forwards.

“Well you know he’s going to start at the rookie camp. So let’s see how he does there,” Chiarelli said during a press meeting to discuss the new six-year contract extension for center David Krejci. “And he’s obviously a skill-and-speed package. Take it slowly. You don’t really want to put him in a high-level spot quite yet. Let’s see how he does in rookie camp and at the Nashville rookie camp. And if he lights it up, maybe he gets into the upper lines to start. So we’ll see.”

Such is the Bruins’ predicament right now. On the one hand, they’ve locked up Krejci as the last piece of their own “core four” for the remainder of this decade, along with fellow center Patrice Bergeron, defenseman Zdeno Chara and goaltender Tuukka Rask. On the other hand, their 2014-15 lineup currently has enough holes that a right-shooting kid who has yet to play an NHL game could find himself on the right side of Krejci and left winger Milan Lucic on opening night.

Krejci’s new contract, which will count as a cap charge of $7.25 million through the end 2021, is only surprising to those not paying attention to what a top-two center in the NHL commands on the open market. We all saw what Paul Stastny commanded from the St. Louis Blues in July (four years, $28 million) and what Jonathan Toews (eight years, $84 million) got from the Chicago Blackhawks this summer before the last year of his prior contract. Colleague Michael Hurley has already explained that Krejci’s deal is at or below market value. I would only add that next year’s unrestricted free agent pool — because most teams are now locking up their best players early and for deals longer than five years — is bereft of centers and would’ve counted Krejci as its best pivot had he gone to market. Now Dallas Stars center Jason Spezza, who’ll be 32 next June and already carries a cap charge of $7 million, might be the lone No. 1 center on the market.

No, the term or compensation the Bruins are throwing Krejci’s (or Bergeron’s, Chara’s or Rask’s) way is not the problem here. The problem will be finding the right players to put around those core pieces while staying under the salary-cap ceiling and maintaining a championship-caliber lineup. Already Chiarelli has run into some trouble getting new contracts for entry-level free agents Reilly Smith and Torey Krug this year. After the Bruins’ signing of restricted free agent Matt Fraser to a one-year, two-way deal Friday, Smith and Krug are the only players without contracts.

Chiarelli said he expects both players will be at camp when festivities commence Sept. 18. But there’s always the chance of a holdout. And it’s difficult to see how the Bruins, with a little less than $4 million in cap space, can get both of those players coming off breakout years in the NHL into the fold without a trade happening to clear some space. This is a scenario the Bruins, as Chiarelli pointed out, have been in before. Remember when they traded Matt Hunwick for Colby Cohen, and when they traded Marco Sturm for nothing? Well, we might be in for more trades like that soon. Those deals didn’t set the Bruins back from their plan and might not in the future as long as Chiarelli and his staff bet right on the best young talent they have coming down the pipeline and can add to the mix through trades and amateur signings.

This is a theme I’ve returned to several times this offseason, but the Bruins are only going to be as successful as their drafting and signing. When you’re paying a premium to your core and secondary players, you have to cheap out for the rest of the lineup. That means less guys like Chris Kelly, Gregory Campbell and Daniel Paille in the bottom six, and more guys along the line of Matthew Lindblad, Justin Florek and Pastrnak. It might mean replacing Adam McQuaid with Kevan Miller and then replacing Miller with someone younger and cheaper in a year or two. It helps, too, to have some prospects that blossom into top-six forwards or top-four D.

It also means difficult decisions on upcoming unrestricted free agents Carl Soderberg and Johnny Boychuk in 2015, and Loui Eriksson and Milan Lucic in 2016. It’ll be Chiarelli’s decision to let them walk, trade them or re-sign them without clogging up the works.

With three-year entry-level deals and pricey second contracts now the norm, the Bruins have to have another wave of young, cheap talent coming up beyond this current group. And so on.

Should Pastrnak, Loui Eriksson and other candidates for Krejci’s right winger fail to produce, then there’s a reason to rattle Chiarelli’s cage. But keeping Krejci – and Bergeron, Chara and Rask for that matter – on a fair market deal for the foreseeable future is a reason to celebrate. Making those deals is the easy part of roster building.

It’s the rest of the roster that’s difficult to formulate, and Chiarelli has about a 50-50 track record in that realm. If he feels to improve that track record, then it’ll show in the Bruins’ year-end results and be a source of major criticism for as long as he’s in the GM’s chair.

Matt Kalman covers the Bruins for CBSBoston.com and also contributes to NHL.com and several other media outlets. Follow him on Twitter @TheBruinsBlog.

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