With training camps for the World Cup of Hockey set to open next week, we've started our look ahead to the highly anticipated preseason tournament.

Now, we're ranking each team's defensive corps heading into the World Cup.

1. Sweden

Roster: Mattias Ekholm, Oliver Ekman-Larsson, Victor Hedman, Niklas Hjalmarsson, Erik Karlsson, Hampus Lindholm, Anton Stralman

Breakdown: As we're continually learning, the best defense in the NHL is out-possessing your opponent. Sweden has built a possession juggernaut with this defensive corps.

To think that this team played for the gold medal two years ago in Sochi without Hedman's services and with Ekman-Larsson as a bit piece is incredible. Now they have both of those players in their prime and probably in top-four roles.

Also at the top of their depth chart, there's Karlsson, who is easily the league's most dynamic defenseman. You look at the minutes he logs, the positive impact he has on his team's offensive attack and his impact on possession, there are few defensemen in the NHL that can match his value.

karlssonworldcup.jpg
Erik Karlsson will lead a loaded Swedish blue line at the World Cup. USATSI

But this is not an all flash and dash defense. Hjalmarsson is a three-time Stanley Cup champion and a terrific defensive defenseman who blocks shots and plays the physical game without being overzealous about it. Then there's Stralman, a do-everything blueliner who is about as reliable as any in the league. Then the depth gets filled out by Lindholm and Ekholm, who have been excelling as they gain more NHL experience.

This team is going to be really difficult to play against because of how well they'll move the puck.

2. Canada

Roster: Jay Bouwmeester, Brent Burns, Drew Doughty, Jake Muzzin, Alex Pietrangelo, Marc-Edouard Vlasic, Shea Weber

Breakdown: The gap between Canada and Sweden is very thin and probably would have been non-existent if Duncan Keith didn't have to drop out of the tournament.

Where Sweden separates itself is in the dynamic element of their blue line. Canada will counter with a blue line that trends more toward the defensive and definitely more physical.

Drew Doughty, Brent Burns and Shea Weber still bring the offense, so it's not like Canada is lagging far behind. On top of that, Doughty can do it all and on this team he won't have to play nearly as much as he does with the Kings, which could make him even more effective. Weber will probably get a top-four role and Burns is going to be an obvious power-play weapon.

Meanwhile, the club has one of the best shutdown defensemen in the game in Marc-Edouard Vlasic, who can match up well with anyone. Alex Pietrangelo also should get quite a few of the tougher defensive matchups. Then there's another jack of all trades in Jake Muzzin and another shutdown defenseman in Bouwmeester to fill out Canada's depth.

There's no threatening Canada as the tournament favorite, but the blue line is one area where it has met its match.

3. USA

Roster: Dustin Byfuglien, John Carlson, Erik Johnson, Jack Johnson, Ryan McDonagh, Matt Niskanen, Ryan Suter

Breakdown: Despite some puzzling decisions for the U.S. blue line, this group still looks like it belongs in the top three. It is vastly different from the blue line that Team USA took into Sochi in 2014 and like Canada it focused more on defensive aspects for the World Cup.

This remains very much Ryan Suter's blue line. He should log a ton of minutes, play in all situations and set the tone defensively for the U.S.

One of the key additions is Byfuglien, who is the most dynamic offensively of USA's defensemen. He might be used a bit more selectively, but there's no doubt USA loves his scoring ability and his intimidating body checks.

Meanwhile, Washington Capitals teammates Niskanen and Carlson are terrific two-way defensemen who should play substantial roles on the team. McDonagh should have a pretty significant role as well, just as he did in Sochi.

This isn't the best defense Team USA could have brought into this tournament, but there is still enough talent on it to offset some of the more questionable roster decisions.

4. Team North America

Roster: Aaron Ekblad, Shayne Gostisbehere, Seth Jones, Ryan Murray, Colton Parayko, Morgan Rielly, Jacob Trouba

Breakdown: When the 23-and-under team was announced as part of the World Cup, many wondered if this team would get smoked. After seeing the roster, they actually might have a chance to compete. Inexperience is the lone separator for this team's blue line, because the talent is most definitely there.

Ekblad is already on his way to being one of the top defensemen in the league and is a natural No. 1 for this club. Meanwhile, Jones is stating his case to be the cornerstone defenseman Columbus has been longing for and teammate Murray might be with him every step of the way.

This D corps also has two incredibly dynamic offensive talents that could be great on the power play and in helping push the pace. Gostisbehere, a Calder finalist last season, could be the X factor for this team, while Rielly is one of North America's most experienced blueliners. Then there's some snarl with Jacob Trouba and size with Colton Parayko, who looked excellent in the playoffs last season.

This is a very well-balanced defense that may only be held back by inexperience. That said, this group is good enough to help North America potentially pull off a surprise.

ekbladwc.jpg
Aaron Ekblad will be a big part of Team North America's blue line. USATSI

5. Russia

Roster: Alexei Emelin, Dmitry Kulikov, Alexey Marchenko, Andrei Markov, Nikita Nesterov, Dmitry Orlov, Nikita Zaitsev

Breakdown: With Russia's loaded forward group, this defense merely has to be serviceable and give their goaltenders a chance. That's about what we should expect from them, too.

Markov is slowing down a little at this point in his career, but looks like he could still be the No. 1 for this team. Meanwhile Marchenko, Nesterov, Zaitsev and Orlov are pretty much just getting started and it's tough to know how they'll handle this level of hockey. Dmitry Kulikov and Alexei Emelin trend more to the defensive side, but both have had some pretty poor numbers in possession.

Markov and Emelin are the only players that were on the most recent Olympic team. The younger players are going to be challenged greatly.

6. Team Europe

Roster: Zdeno Chara, Christian Ehrhoff, Roman Josi, Dennis Seidenberg, Andrej Sekera, Luca Sbisa, Mark Streit

Breakdown: The top four defensemen for this team are fine. Josi is becoming one of the best blueliners in the league, Chara remains an intimidating presence and both Sekera and Streit are still legit top-four NHL defensemen. After that, the drop off is significant.

The lack of depth is a big reason this team dropped to sixth. Ehrhoff and Seidenberg still don't have contracts for next season and both had pretty poor years in 2015-16. Luca Sbisa struggled mightily for the Vancouver Canucks as well. Because of the lack of depth, there's more pressure and more ice time on Josi and Chara, which could be overly taxing given the level of competition.

7. Finland

Roster: Jyrki Jokipakka, Sami Lepisto, Esa Lindell, Olli Maatta, Ville Pokka, Rasmus Ristolainen, Sami Vatanen

Breakdown: Gone are the years of Kimmo Timonen and Sami Salo anchoring seemingly every Finnish national team's blue line. This Finland D corps has only one player over the age of 25 -- former NHLer Lepisto, who is 31. The rest of the team has been turned over to the kids and most of them are really good at moving the puck. Experience is a concern here, though.

Ristolainen and Vatanen should be leaders on this young blue line based on their recent NHL performances. Maatta just won the Stanley Cup. Others like Jokipakka, Lindell and Pokka all have limited NHL experience.

Finland's blue line has a lot of potential, but there are enough unknowns that it's hard to put them ahead of defensive groups with more experience. They should still be fun to watch.

8. Czech Republic

Roster: Radko Gudas, Michal Jordan, Michal Kempny, Zbynek Michalek, Jakub Nakladal, Roman Polak, Andrej Sustr

Breakdown: Welcome to the land of depth defensemen. While every single one of the other teams in this tournament has at least one player that is a top-pairing defenseman on his NHL club, the Czechs have none. They barely have any top-four defensemen, unless you count Zbynek Michalek and Radko Gudas, who occasionally slot in the top four for their respective NHL teams.

The Czechs are in tough shape to do much of anything in this tournament and a big reason for it is this shallow blue line.