Depth Question: The challenge of constructing a durable NHL blueline

The Bruins are down 2-0 in their series with the Hockey Club from Montreal, facing two games on the road. Zdeno Chara played sick the first game and missed the second entirely. Chara is an especially significant case, but any team losing its top defenseman faces the ripple effect challenge: Who steps in to fill his place? (And who steps into fill that guy's place? And then that guy's place ... on down through the lineup.)

Understandably, some Bruins followers are upset that there aren't really impressive D-men ready to step in for the Bruins. I see this among hockey fans quite often. Every time I do, I think the same thing: Easier said than done.

As Islanders fans know all too well, defensemen tend to get injured. Even excluding the three "ATO #55"s the Isles used at the end of this season, the Islanders have used 12 or more different defensemen in each of the past three seasons. Thanks to salaries, the salary cap, veteran expectation, and NHL waiver rules, being prepared to go even 10 deep on the blueline requires threading a lot of organizational and precedural needles. Most teams are left vulnerable because most teams can't afford to carry a happy NHL-caliber defenseman or two in the press box each night -- not to mention the mix of unproven or proven mediocre bodies they have stored in the minors.

The post linked above argues, with some merit, that the Bruins were exposed when the B's left themselves with Shane Hnidy and rookie Steven Kampfer as the next in line. But one of the descriptions gets right to my point [emphasis mine]:

Well Kampfer became a lineup casualty himself by suffering a knee injury during an AHL conditioning stint last week. Nonetheless, he had played his way out of the lineup by making the type of decisions with the puck you expect out of a first-year pro defenseman. And his defensive game is not ready for the NHL playoffs.

Aye, that's the rub. Unless you're a Cup favorite and some fantastic NHL veteran would love to be "just one of the guys" on one last playoff run, which quality defensemen, exactly, want to come into your camp saying, "I want to win that seventh D position."?

Rookie Defensemen are Unpredictable and Mistake-Prone.

What's one option for injury replacements? Calling up prospects from the AHL. Why are prospects in the AHL? Because you don't know what they can deliver. You'd rather them learn the pro ropes in a league where their mistakes don't cost you NHL games.

Sometimes this means you call up Travis Hamonic in the first year of his ELC and discover he's ready to serve. More often it means you're calling on Dustin Kohn or Mark Flood and hoping the injured guys heal right quick.

Healthy Scratch Veterans are, by Definition, Not 'Top Six.'

Bruno Gervais did not spend time in the press box this year because the Islanders just wanted to have a fine NHL defenseman around in case something bad happened. He spent that time because on several nights he was not one of the six best available options. (Note: Gervais also suffered two significant injuries this season, so do not misread his 53 GP as a sign he was healthy scratched for 29 games. A good chunk of that was Islanders Face and another stint at year's end was a foot issue from a shot block.)

When you think about how many blueliners the Isles went through this year -- rookie Travis Hamonic grabbed a role at age 20, Ty Wishart made a case after coming over in the Roloson trade -- being healthy scratched at all says something about the status of Gervais, a six-year veteran of 331 games and still just 26. Granted, injuries forced Gervais to play on his off-side much of the year, but if he were an essential contributor on his natural side, then someone else might have been moved instead.

Whatever you think of Gervais (e.g. "He's a solid depth defenseman and always has been," or "He's in the captain's chair of my nightly scapewagon," or "I used to hope for more but no I'm not sure at all"), all can probably agree that at one time it was expected he would be a regular at this age.

...which might, actually, make him the type of depth D-man teams look for, warts and all. (Another example: Mike Mottau, the defenseman who disappointed many after being signed late thanks to Mark Streit's training camp injury. Mottau averaged 78 games per season on Devils playoff teams the previous three seasons.)

Because unfortunately, you just can't stash outstanding defensemen in the #7 and #8 hole. In times of blueline health but forward injuries, roster flexibility demands you be able to move those guys to the AHL, which means they either must be questionable enough to pass through waivers unclaimed or so green that they don't require waivers at all. Beyond that, we all know that highly qualified NHL defensemen do not take kindly to life as constant healthy scratches. (Hell, even Mike Commodore and his diminished skills couldn't tolerate but a few weeks of it in Columbus before demanding a trade.)

Sometimes, the Problem is Even Higher up the Chart

And sometimes it's not even #7 and #8 on the depth chart that you're worried about -- it's #5 and #6. In last year's playoffs, the Flyers fell into the mode of relying extremely heavily on their top four defensemen. Their top four guys each averaged over 24 minutes per game, while Peter Laviolette did whatever he could to avoid using Ryan Parent, Lukas Krajicek or Oskars Bartulis in meaningful situations, sticking them in the corner like redheaded stepchildren when polite company come over.

Parent, you'll remember, was once a touted 1st-round pick (18th overall, 2005) as a member of Nashville's army of impressive young D prospects. Interestingly, they eventually found him expendable, and so did the Flyers and, implicitly, the Canucks. Parent played four NHL games this year at age 23, despite constant injuries to the Canucks' back line.

So what did the Flyers do to avoid that situation again? They assumed the premium of Andrej Meszaros and the absurd $16 million and four years left on his contract. (Elsewhere on the Lightning castoff shelf, the Flyers also have $1.7 million per year for three more years (including 2010-11) on Matt Walker stored in the minors.) All told, the Flyers have $24 million in cap hit allocated toward their top eight, and of course the bottom two in that chart are Bartulis and "journeyman" Nick Boynton at essentially league minimum wages.

The kicker? Chris Pronger is injured now and seems likely to miss at least the first three games of their first-round series (and I'd bet he misses more). They're better-equipped to withstand that loss this season than they were last season, but that doesn't keep Flyers fans from panicking over the sight of Danny Syvret logging playoff minutes.

Stack Carefully, Hope for the Best

Injuries will happen, so you need to prepare by building depth. But depth is easier begged than done, so doing it right involves a mix of solid NHLers (and luck), veteran fill-ins (and luck) and young prospects who you hope might be able to step up and, if not, who you know at least can be returned to the AHL without losing them. That also, incidentally, costs money.

Occasionally, you have to make a minor league move for a guy like Dylan Reese -- who has both satisfied and disappointed, depending on the day. The Islanders grabbed Reese in a swap of AHLers late last year when Andrew MacDonald was hurt right after they traded Andy Sutton.

Ultimately, this means sometimes you're going to find gems in Andrew MacDonald or (ahead of schedule) Travis Hamonic. Other times, you're going to have to make do with Dylan Reese, Mark Katic or Bruno Gervais -- in whatever trajectories you catch them in their careers.

I'm a big proponent of building team depth at this position to withstand the inevitable injuries. But whether you're a Cup contender of team #26, even with the best laid plans, getting it right to withstand 82 games plus requires a lot of hope and luck.