From the earliest days of training camp, Coach Adam Oates made it clear that his system was designed for the protection and involvement of the defensemen.

Ideally, blueliners will have the extra time to make the proper play to get the puck out of their own end and avoid the hits that come with a punishing forecheck. It was also critical for each defenseman to join the play in the offensive end, pinching to help maintain possession and adding more shots from the point. The defensemen accounted for 27 goals and 91 points in the regular season and gave the Capitals’ offense an extra element that makes it all the more difficult for an opponent to try and shut the team down.

Of the defensemen who finished the season with the Capitals, six are under contract for 2013-14 and Washington is expected to re-sign restricted free agent and top-four mainstay Karl Alzner. While Washington doesn’t need to overhaul its defensive corps this summer, the possibility for changes on the depth chart remain as the team could bolster its lineup with addition of youth or perhaps seek out some more experienced depth.

Prospects Dmitry Orlov and Tomas Kundratek spent a large portion of the season in Hershey, but both appear ready to step into more prominent roles. And then there’s the question of what to do with Jeff Schultz, who saw his game appearances drop for a second consecutive season, but has one year remaining on his current contract. Even assuming Alzner returns, the Capitals could benefit from the addition of an experienced all-around top-four defenseman. But then again, what team couldn’t?

If you’ve missed any of the previous breakdowns, check them out here: Forwards Part I, Forwards Part IIGoaltendingUnrestricted free agents and Restricted free agents.

(Greg Fiume/Getty) Mike Green celebrates his overtime-winner in Game 2 of the Eastern Conference quarterfinals.

Mike Green
2013-14 salary cap hit: $6,083,333 | Age: 27

What a difference a healthy Green makes for the Capitals. After being severely limited in each of the previous two seasons by a host of injuries and sitting out 13 games this year with a groin strain, Green returned to the lineup in mid-March finally confident that his body would hold up to the strain of the NHL.

Green recorded 10 of his 12 goals – good for best in the league among defensemen – in the final 19 games of the regular season and scored twice in the seven-game series against the Rangers. He was once again the commanding presence patrolling the blue line both at even strength and on the power play, setting up teammates for one-timers and unleashing his own powerful shot from the point.

While the statistics are one thing, Green brings a dimension to the Capitals’ game that simply cannot be replaced. From the respect opposing defenses must give him as a scoring threat at the point to his ability to serve as a one-man breakout and ensure Washington doesn’t spend unnecessary time trapped in its own zone, Green’s skillset helps the Capitals tick.

Staying healthy is arguably the biggest obstacle for Green moving forward. He fits well within Oates’s system and seemed reinvigorated by learning from the Hall of Fame center, along with assistant coaches Calle Johansson and Tim Hunter. As long as he’s able to avoid serious injury there’s no reason to believe Green can’t continue trending upward, logging the significant ice time and critical role that he has always been counted on to provide.

(Evan Vucci/Associated Press) (Evan Vucci/Associated Press)

Karl Alzner
2013-14 salary cap hit: RFA | Age: 24 (Turns 25 on Sept. 24)

Alzner, like most of the Capitals, didn’t get off to a strong start in the shortened season – he was on the ice for 17 of 36 goals against in the first 10 games. It was an unexpected turn for Alzner, who is perhaps the most reliable and steady player in Washington’s lineup, but one that subsided as he developed a familiarity with the new system.

For the first time in his NHL career he worked primarily with someone other than Carlson this season, instead serving as the defensive counterbalance on a pairing with Green.

Assuming Alzner re-signs with Washington as expected, he’ll continue to take on tough matchups 20 minutes a night and, more often than not, do a quiet job of limiting opposing offensive talent. As solid as Alzner is, the question remains: How can he improve his game? He’s never going to light up the scoresheet or become a bruising presence along the boards, but Alzner has expressed his intent to improve his stick work and play with the puck.

“I started to feel better with the puck. I started to carry it a little bit more, lugging it out of the zone occasionally and trying to jump up in the play, and that’s something that I never ever did,” Alzner said. “You wouldn’t catch me crossing the offensive blue line. I still panic when I get across that line. It’s something that I’m trying to do more, trying to have a little more confidence with that.”

(Justin K. Aller/Getty) (Justin K. Aller/Getty)

John Carlson
2013-14 salary cap hit: $3,966,667 | Age: 23

Carlson continued to anchor Washington’s shutdown pairing, even if he was separated from long-time defensive partner Alzner. He was on the ice for 61 goals against and struggled early on in the season, but Carlson’s overall play leveled out over the course of the year.

While he recorded six goals and 16 assists, Carlson will never carry the offensive mantle or expectations that Green does and he isn’t a stay-at-home defenseman like Alzner, either. But the balance in Carlson’s game and his ability to play in all situations – he’s the only Capitals blueliner to average over two minutes on both the penalty kill and the power play — makes him a critical pillar of the defensive framework.

As much as Washington relies on Carlson, what it needs most from the 23-year-old it trusts to face tough matchups night in and night out is consistency. Splitting him from Alzner allowed the coaching staff to better balance the defense and provide more options, but it’s hard not to wonder if Carlson could benefit from the addition of another true top-four defenseman.

(Adam Hunter/Reuters) (Adam Hunter/Reuters)

John Erskine
2013-14 salary cap hit: $1,962,500 | Age: 32 (Turns 33 on June 26)

Erskine took advantage of the fresh start offered by the new coaching staff and had one of his best seasons in seven years with the Capitals. He took on a consistent role as a top-four defenseman, often skating with Carlson, and saw his average ice time rise to a career-high 18:28.

It was responsibility that many assumed Erskine was no longer capable of and allowed him to bring his brand of rugged play to the forefront, whether he was battling for pucks in the corners or shoving opponents out of the crease. Erskine posted three goals and three assists in 30 regular season games as well.

Erskine showed he is capable of handling a heavy workload, but the 32-year-old faltered in the postseason and was on the ice for eight Rangers goals. Is it realistic to expect Erskine to fulfill a top-four role in a full 82-game season next year? Or would he be better used in a less prominent role?

(Bruce Bennett/Getty) (Bruce Bennett/Getty)

Jack Hillen
2013-14 salary cap hit: $700,000 | Age: 27

After missing 25 games with an apparent shoulder injury he suffered in the season opener, Hillen returned to the lineup in mid-March to play anywhere from 14 to 25 minutes per game on either the second or third pairing. He brought some unexpected offense as well, adding three goals and six assists – all in the final 14 games of the regular season.

Hillen’s strong skating ability helped him fit well into Oates’s system,  a fact that played a part in his receiving a two-year, $1.4 million extension from the Capitals that will keep him in the fold through 2014-15 at a salary-cap friendly rate.

(Toni L. Sandys/The Washington Post) (Toni L. Sandys/The Washington Post)

Steve Oleksy
2013-14 salary cap hit: $541,667 | Age: 27

Oleksy’s arrival in the NHL after years of toiling in various minor leagues was the feel-good story of the season for the Capitals. That he was able to not only appear in the lineup but play in 28 regular season games and each contest in the first round of the playoffs, dishing big checks, adding grit, occasional offense and minimizing his mistakes was an unexpected boon for the blueline.

Where Oleksy, who recorded one goal and eight assists in the regular season, truly excelled was at keeping himself out of trouble. Mistakes are par for the course for anyone finding their way in the NHL for the first time, Oleksy managed to limit his own errors by making smart, simple decisions that played to his strengths.

Now that he got his foot in the NHL door, Oleksy will have to prove he can stay there. For Oleksy it will be key to improve his skating ability and remain the “sponge” that picked up every piece of information from the coaching staff to better himself.

(Bruce Bennett/Getty) (Bruce Bennett/Getty)

Tomas Kundratek
2013-14 salary cap hit: RFA | Age: 23

Kundratek showed he could hold his own in the NHL during a 25-game stint with the Capitals this season. A strong skater who is confident with the puck, Kundratek held his own as he went through the growing pains of a steady role in the NHL for the first time in his career. While there were times where he was overexposed against highly-skilled opponents, Kundratek asserted himself within the organizational depth chart as he helped Washington weather numerous injuries on the blue line.

Where he fits into the equation next season may depend on the health and performance of the other right-handed shots on the depth chart, but it certainly wouldn’t be out of the question to see Kundratek spend more time with the Capitals next season.

(Glen Gray/Associated Press) (Glen Gray/Associated Press)

Dmitry Orlov
2013-14 salary cap hit: $900,000 | Age: 21 (Turns 22 on July 23)

Sidelined by two concussions while playing in Hershey during the NHL lockout, Orlov made only a brief appearance (5 games) with the Capitals this season. Under Oates, who insists defenseman play their strong side, expect to see Orlov lining up on the left rather than the right where he has often appeared throughout his career.

If Orlov can stay healthy the hard-hitting defenseman with the booming shot from the point should be able to bolster the Capitals’ lineup, but the upcoming year looms large. The 2013-14 season is the final year of his entry-level contract and Orlov will be looking to stick in the NHL for the majority of the season.

(Keith Srakocic/Associated Press) (Keith Srakocic/Associated Press)

Jeff Schultz
2013-14 salary cap hit: $2.75 million | Age: 27

Schultz saw his game appearances (26) and ice time (14:15) drop dramatically for a second straight season and his role diminished even further than it was during Dale Hunter’s tenure.  Once a regular part of the Capitals’ top four, Schultz has been pushed down the depth chart in favor of more agile and better puck-movers.

With one year remaining on his four-year, $11 million contract and a sizable salary cap hit, could Schultz be a potential option for a compliance buyout or perhaps part of a trade? It would give Washington, which already has more than $58 million committed to 19 players for next season, a little more wiggle room under the $64.3 million salary cap and perhaps give Schultz a chance to earn playing time elsewhere.