Ottawa Senators defenseman Erik Karlsson suffered a laceration to his left Achilles, will need surgery and is out indefinitely, the team announced on Wednesday.
Karlsson was injured in the second period of the Senators' 4-2 loss to the Pittsburgh Penguins after he was cut on the leg by a skate blade of Penguins forward Matt Cooke as the two got tangled along the boards.
Karlsson, who was last season's Norris Trophy winner as the NHL's top defenseman, leads all defensemen with six goals this season, including scoring three times in his previous four games. He also has four assists.
The Senators are 7-5-2 and in sixth place in the Eastern Conference.