NHL: Top 5 Defensive Units Heading Towards Draft Day

With the NHL draft set to take place this Friday and Saturday, the landscape of the league will be significantly different a week from now.

Although forwards such as Rick Nash and Nail Yakupov are dominating headlines, it will be blueliners that make the biggest pre-free agency impact.

Nicklas Lidstrom has already retired, and Chris Pronger may be doing so soon. Ryan Murray will likely go second overall to Columbus on draft day, and he'll only be the first of 10-plus defensemen who could go in the top 20 picks.

Given that, the elite defensive units in the league could belong to different teams next Sunday, so it's important to put the current ones on record while we still can.

Honorable Mentions

Buffalo: Christian Ehrhoff, Tyler Myers and Jordan Leopold were as injured as they were effective last year, but they still make a nice-looking group. The Marc-Andre Gragnani trade cost them a solid future, but if Ehrhof settles and and Myers gets healthy, they'll have a scary top unit.

Montreal: P.K. Subban continues to blossom, while Josh Gorges and Alexei Emelin were defensive forces. A Tomas Kaberle return to form and an Andrei Markov return to health would make this a top five unit.

St. Louis: Kevin Shattenkirk and Alex Pietrangelo are two of the league's best young defensemen, making everyone forget about Erik Johnson. With Barret Jackman and Roman Polak, the Blues had a great looking top four, but Jackman and Carlo Colaiacovo must be re-signed.

Nashville: The Preds have the best top-two defensemen in the NHL with Shea Weber and Ryan Suter. Hal Gill, Francis Bouillon and Kevin Klein make the unit elite. Unfortunately, Weber, Suter, Gill and Bouillon are all free agents, making this unit impossible to retain on Nashville's budget.

Pittsburgh: The Penguins have awesome blueline depth, with Brooks Orpik, Paul Martin, Kris Letang, Deryk Engelland, Zbynek Michalek and Matt Niskanen. They don't crack the top five for lack of a dominant top pairing and offensive firepower.

Boston Bruins

The Bruins have a deep group of gritty defensemen who will just hit you and block shots until you throw in the towel.

Dennis Seidenberg, Zdeno Chara, Adam McQuaid, Johnny Boychuk and Greg Zanon all delivered over 100 hits last season. Only Chara didn't also block 100 shots (87), but his 12 goals and 40 assists made him one of the most dominant two-way defenseman in the NHL.

Each of those defensemen was plus-15 on better besides Greg Zanon, who came over from Minnesota.

Looking to next year, the Bruins will have a couple tough free-agency decisions to make with Zanon and Joe Corvo. Even if they lose both, Chara, Seidenberg, McQuaid and Boychuk will make a nasty top four.

What could knock them off this list before next season: The loss of Zanon and Corvo. They'll remain very good, but not a top-five unit.

Los Angeles Kings

The Kings just won the Stanley Cup with dazzling defense after finishing the regular season with the league's second-best goals against average. Their blueline is a big part of that, with Drew Doughty, Willie Mitchell and Slava Voynov all turning in excellent seasons both offensively and defensively.

Matt Greene's 241 hits allowed the top four to play more freely, although Doughty also dished out 124 of his own.

There are two reasons Los Angeles doesn't rank higher than fourth. The first is that Jonathan Quick and possibly the best defensive forwards in the Western Conference were equally responsible for the team's defensive dominance.

The second is the Jeff Carter trade, which left LA without their second-best defenseman in young stud Jack Johnson.

Moving forward, the Kings blueline looks elite with or without Johnson. Doughty, Voynov and Alec Martinez are all 24 or younger, while the farm system features excellent defensive prospects such as Derek Forbort and Jake Muzzin.

What could knock them off this list before next season: The decline of Rob Scuderi and long-term impact of losing Jack Johnson.

San Jose Sharks

San Jose had its worst season in years, but it wasn't due to bad defenseman. Dan Boyle had a 48-point season, Marc-Edouard Vlasic dominated his own zone and Brent Burns transformed the blueline for the better.

However, San Jose still had some defensive problems during the season. While Burns was transformative, he wasn't the player he was in 2010-11 with Minnesota. Douglas Murray was overmatched as a top-four defenseman, and Colin White was a dreadful third-pairing partner for Justin Braun.

But San Jose has traded for the rights to Brad Stuart, and that changes everything.

Assuming Stuart signs, the Sharks will have an elite top four, with offensive monsters Boyle and Burns paired with defensive studs Stuart and Vlasic (who both are also capable offensively). This proper alignment should help Burns return to All-Star form.

This also pushes Douglas Murray down to the third pairing, where him and Justin Braun appear to be among the league's best bottom units.

What could knock them off this list before next season: Brad Stuart not signing, Douglas Murray being traded and no one brought in to replace him on the third pairing.

New York Rangers

The Rangers went through much of the season without All-Star defenseman Marc Staal, yet they still featured one of the league's most effective units. Dan Girardi (28 years old), Ryan McDonagh (23) and Michael Del Zotto (21) took on a ridiculous average of 24:47 of ice time, but the way they played made it well worth it.

Girardi and McDonagh each blocked over 180 shots and had at least 37 takeaways. Girardi dished out 211 hits, while McDonagh and Del Zotto finished with 118 and 156, respectively.

Marc Staal returned to play great two-way hockey late in the season, while Anton Straiman and Michael Sauer were solid in his absence. Steve Eminger and Stu Bickel provided depth and physicality.

Like Los Angeles, New York was great in large part due to its goaltending and defensive forwards. However, it ranks higher than the Kings because it still possesses all of its prized young assets on the back end.

What could knock them off this list before next season: Terrible trades or offseason injuries. It's possible that their young studs regress next year, but for now, this unit looks elite.

Vancouver Canucks

The Canucks appeared to get worse defensively after losing Christian Ehrhoff to free agency last summer. They didn't. In fact, their blueline may have been better.

Ehrhoff's 50 points from 2010-11 were gone, but Alex Edler's career-high 49 made up for it. Kevin Bieksa (44 points)  and Dan Hamhuis (37) joined Edler to give Vancouver an unheard of three 30-assist defenseman. Sami Salo added nine goals with his hard shot, and the Canucks had the league's best offensive blueline by far.

This doesn't mean the unit wasn't strong defensively. The three 30-assist getters were also own-zone forces, each at least blocking 100 shots, laying 100 hits and grabbing 29 takeaways. Aaron Rome, Andrew Alberts and Keith Ballard all shared third-pairing time, combining to dish out 216 hits in only 134 games.

Assuming the top three return and the depth isn't decimated, this will remain the top defensive unit in the NHL.

What could knock them off this list before next season: Terrible trades or offseason injuries. Even losing free agents Salo and Rome won't take this unit out of the top five.