Andrej Sekera had surgery to repair a torn Achilles tendon on Tuesday and is out indefinitely for the Edmonton Oilers.
"It's a significant injury," Edmonton general manager Peter Chiarelli said.
The 32-year-old defenseman, who was injured last week during offseason training, had eight assists in 36 games last season. He missed the first 34 games after tearing his ACL in the 2017 Stanley Cup Playoffs.
"We expected him to bounce back from his ACL and have him healthy for the year, so this is a tough blow," Chiarelli said. "We'll see how the recovery unfolds, but it's incumbent on us to look for replacements whether they're internal or external. We have the ability through long-term injury reserve to replace that salary and we'll see how that goes. It's definitely something that's a big blow for us."
Video: Andrej Sekera is out indefinitely with torn achilles
Sekera signed a six-year contract with the Oilers as an unrestricted free agent July 1, 2015.
"It's tough at this time in the summer to replace a player like Sekera, so we'll do the best that we can do with the resources that we have and we'll see where it goes," Chiarelli said.
Selected by the Buffalo Sabres in the third round (No. 71) of the 2004 NHL Draft, Sekera has 232 points (45 goals, 187 assists) in 683 regular-season games with the Oilers, Los Angeles Kings, Carolina Hurricanes and Sabres. He has four points (two goals, two assists) in 19 playoff games.
The Oilers selected defenseman Evan Bouchard with the No. 10 pick in the 2018 NHL Draft.
"We're going to look at everything," Chiarelli said. "He's a young player (18) and to be able to expect him to make the team is going to be a challenge for him, but he's got that competitiveness. But to make the team and replace Andrej Sekera, that would be even more to expect of him."