Remember when the Boston Bruins locked up Zdeno Chara to a seven-year contract extension that wouldn't expire until after the defenseman's 40th birthday? 2018 felt like an eternity's length away.

Yet here we are, entering the 2013-2014 season with the now 36-year-old captain still leading the way for Boston's defense.

Age is a very weird thing in professional sports. When Chara lifted the Stanley Cup in Vancouver on June 15, 2011, he was 34 years old. Not much was being made of his age at that point, especially when compared to the dozens of "last chance" stories concerning the then 37-year-old Tim Thomas, or 41-year-old Mark Recchi.

Should the Bruins make yet another run at the Cup this season, that's sure to change.

It's long been assumed that the Boston Bruins would remain an elite, Cup-contending team for as long as Chara could support the load. That window could be closing. Chara is no doubt the best conditioned athlete in the NHL, as well as one of the league's top defenseman, but we saw the earliest signs of age catching up to the defenseman during the Chicago series.

That interview, man.

"They think they've got you tired, they think they've got you out. Do they?"

"…We'll see about that."

That answer, in hindsight, was yes. In the Stanley Cup Final, Chara tallied 1 goal, 3 assists, and a -5 +/- rating while averaging just under 30 minutes a game in ice time. The will was there, the desire to win was there, but the results were not.

Entering year three of that seven-year deal signed back in 2010, Chara is the only (!) Bruin defender under contract after 2015. The contracts of Johnny Boychuk, Adam McQuaid, and Dougie Hamilton all expire the year after next, while Dennis Seidenberg, Torey Krug, and Matt Bartkowski are all entering the final year of their current deals.

That's a lot of uncertainty for a defensive core that's been as stable as that of any team in the league for the past seven years.

Hockey Prospectus recently ranked Boston's prospect system at 21st in the league, with only Torey Krug and newly acquired Joe Morrow named as top defensive prospects. General manager Peter Chiarelli and company decided to take the first steps in improving their future by firing scouting head Wayne Smith earlier this month.

When Dougie Hamilton was drafted at 9th overall in the 2011 NHL draft, the popular thinking was that Boston had just selected the heir to the defensive throne. Then again, the same was said back when Boston selected Kyle McLaren 9th overall in 1995.

"Quick, burly 21-year old Kyle McLaren has proved that he's ready to anchor the defense if 37-year old Ray Bourque, who comes back for his 20th season, ever retires"- Sports Illustrated, 1998 Boston Bruins Prospect Report

The future never quite arrived for McLaren. He played for Boston until 2002, then signed with San Jose where he led a respectable NHL career before quietly retiring. You may remember him for his most (in)famous moment as a Bruin:

Needless to say, Boston is looking for a little more out of Hamilton than they got from McLaren. Hamilton may still considered the future, but with the end in sight for the man known as "Z", Boston must start preparing for a time when they won't have their 6'9" safety net. And for the time being, that preparation starts with the young man wearing #27.