Ottawa Senators defenseman Erik Karlsson (65), of Sweden, stands next to Washington Capitals center Marcus Johansson (90), of Sweden, during the third period of an NHL hockey game, Thursday, April 25, 2013, in Washington. Ottawa won 2-1 in overtime. (AP Photo/Nick Wass)
Ottawa Senators defenseman Erik Karlsson (65), of Sweden, stands next to Washington Capitals center Marcus Johansson (90), of Sweden, during the third period of an NHL hockey game, Thursday, April 25, 2013, in Washington. Ottawa won 2-1 in overtime. (AP Photo/Nick Wass)
Ottawa Senators left wing Jakob Silfverberg, right, of Sweden, celebrates his goal with teammate Erik Karlsson (65), of Sweden, who got an assist on the goal, during the second period of an NHL hockey game against the Washington Capitals, Thursday, April 25, 2013, in Washington. (AP Photo/Nick Wass)
Ottawa Senators defenseman Erik Karlsson (65) grimaces as he falls to the ice after colliding with Pittsburgh Penguins left wing Matt Cooke, left, during the second period of an NHL hockey game in Pittsburgh Wednesday, Feb. 13, 2013. Karlsson was helped off the ice. (AP Photo/Gene J. Puskar)
Ottawa Senators defenseman Erik Karlsson (65) limps off the ice after injuring his left left in a collision with Pittsburgh Penguins left wing Matt Cooke during the second period of an NHL hockey game in Pittsburgh Wednesday, Feb. 13, 2013. Karlsson did not return to the game. The Penguins won 4-2. (AP Photo/Gene J. Puskar)
Ottawa Senators defenseman Erik Karlsson (65) limps off the ice after injuring his left left in a collision with Pittsburgh Penguins left wing Matt Cooke during the second period of an NHL hockey game in Pittsburgh Wednesday, Feb. 13, 2013. Karlsson did not return to the game. The Penguins won 4-2. (AP Photo/Gene J. Puskar)
Ottawa Senators defenseman Erik Karlsson (65) limps off the ice as a team trainer arrives to help him after Karlsson collided with Pittsburgh Penguins left wing Matt Cooke during the second period of an NHL hockey game in Pittsburgh on Wednesday, Feb. 13, 2013. Karlsson did not return to the game. The Penguins won 4-2. (AP Photo/Gene J. Puskar)
Ottawa Senators defenseman Erik Karlsson (65) grimaces as he falls to the ice after colliding with Pittsburgh Penguins left wing Matt Cooke, left, during the second period of an NHL hockey game in Pittsburgh Wednesday, Feb. 13, 2013. Karlsson was helped off the ice. (AP Photo/Gene J. Puskar)
Senators defenseman Erik Karlsson had surgery to repair his torn left Achilles tendon Thursday and will be out 3-4 months. (Associated Press)
