Ottawa Senators star defenseman Erik Karlsson is out indefinitely after suffering a nasty leg injury on Wednesday against the Pittsburgh Penguins, and his absence from the lineup will be a huge loss for the team and the NHL as a whole.
The reigning Norris Trophy winner was pinned against the boards by Pittsburgh Penguins forward Matt Cooke, whose left skate came down on Karlsson's Achilles.
Unless something changes, the 22-year-old defenseman will miss the rest of the season as he recovers from surgery, according to Ian Mendes of Sportsnet.
Let's examine what kind of impact Karlsson's absence from the Senators lineup will have on his team and the league as a whole.
How the Injury Impacts the Senators
Karlsson scored 78 points in 81 games last season and became the league's best offensive defenseman.
Through 14 games this season, Karlsson already has 10 points (six goals, four assists) and his defense has improved mightily.
When the Senators lost No. 1 center and top forward Jason Spezza to back surgery earlier in the season, Karlsson was under pressure to be even more productive offensively. In the 10 games since Spezza left the lineup, Karlsson had five points (three goals, two assists) and played about 28 minutes per game.
Karlsson ranks in the top 15 in eight important statistical categories among defensemen.
As the league's leading goal scorer among defenseman and the best power-play quarterback in the game, the impact that Karlsson's absence from the lineup will have on the Ottawa offense will be massive.
The team ranked 20th in goals scored and 17th in power-play percentage going into Wednesday's game, and you can expect the Senators to plummet further down the rankings in both categories without Karlsson.
Unfortunately for the Senators, there is absolutely no way to replace Karlsson, especially since the team's second-best offensive defenseman, Jared Cowen, is also injured and hasn't played yet this season.
There's no other defenseman in the league with the same offensive skill set and the ability to put up points as consistently as Karlsson does while also playing almost 30 minutes each night.
Replacing his scoring production from the blue line will have to be a group effort, and veteran defensemen Sergei Gonchar, Marc Methot and Chris Phillips will have to step into a larger role and become more aggressive offensively.
Now that the team's three best offensive players are injured (Spezza, Karlsson and Milan Michalek), the Senators will have to rely even more on star goaltender Craig Anderson to carry the team.
Anderson is a top Vezina Trophy candidate through the first quarter of the season, but having to bail the team out while its offense struggles to score goals will be a difficult challenge for the 31-year-old netminder because he now has to play without his two best defensemen (Karlsson and Cowen). This team will now go as far as Anderson takes them, and that's a lot of responsibility to put on one player.
Senators general manager Bryan Murray has two options to consider with Karlsson injured. He can trade draft picks and/or a top prospect for a top-four defenseman and try to contend in the Eastern Conference even though his two best players may not return until next year, or he can let the season take its course and focus on 2013-14.
Playing for next season is the best option because it would be foolish to rush Karlsson and Spezza back to the lineup when the team would only have a small chance of winning a round in the playoffs.
Murray should keep his valuable assets, such as draft picks and prospects, and prepare for the 2013-14 season with a healthy team that's capable of winning the Northeast Division.
How the Injury Impacts the NHL
Karlsson is a generational talent as a premier offensive defenseman, and he's one of the few blueliners that does something every night that makes you jump out of your seat. He is by far the most exciting defenseman in the world, there's no debate.
His skating, ability to join the rush and score goals and overall playmaking skills (passing, vision, hands) make him must-see TV each night. Karlsson is the kind of player that fills seats at every arena because his offensive ability is so fun to watch.
Fans love to watch games with lots of scoring, and there are few players in the NHL capable of creating more goals than Karlsson.
From a discipline perspective, don't expect this incident to result in a suspension or any changes to current rules.
Cooke has quite a reputation around the league, and was once one of dirtiest players in the game. Following his incident with Boston Bruins center Marc Savard during the 2009-10 season and his lengthy suspension at the end of the 2010-11 season, Cooke changed the way he played; to his credit, he wasn't disciplined once last year.
Cooke was actually the Penguins' nominee for the Bill Masterton Trophy last season, which seemed impossible just a few years ago.
The actions leading up to the injury aren't anything the league is trying to take out of the game. It was a normal hockey play, and unfortunately it resulted in a devastating injury for not only the Senators, but the league as a whole.
Was Cooke intentionally trying to injure Karlsson? The video evidence doesn't show any malicious intent, but only Cooke can answer this question with any certainty.
At the end of the day, Karlsson's loss is a massive one for the entire league. Any time a young, exciting superstar is unable to display his fantastic talents to hockey fans everywhere because of an injury, it's a sad time for the sport.
Nicholas Goss is an NHL Lead Writer at Bleacher Report. Follow him on Twitter.