Boston Bruins defenseman Torey Krug suffered a lower-body injury during Saturday's preseason game against the Philadelphia Flyers and didn't return, the team announced.

Krug suffered a season-ending fractured ankle during the second round of the playoffs against the Tampa Bay Lightning last spring.

He was spotted in a walking boot after Saturday's contest, but head coach Bruce Cassidy said he didn't believe Krug had been suffering any lingering effects from the fractured ankle.

"I have no information on anything bothering him," said Cassidy. "They gave him a timeline on when he could return to play, and it was later. He wasn't going to play the first two games, clearly. That's why he wasn't going to China. That was determined in probably the first week of August ... and then he gets injured again, so hopefully it's nothing serious. But it's tough luck if it is, obviously."

Krug is coming off a career year, compiling 14 goals and 59 points in 76 games last season, and adding 12 more points in 11 postseason contests. The Bruins would likely turn to Matt Grzelcyk or rookie Urho Vaakanainen if Krug misses the season opener on Oct. 3.