Seidenberg injury opens opportunity for Bruins defencemen

The Boston Bruins will open their season without a key defenceman.

Dennis Seidenberg will be sidelined approximately eight weeks, general manager Don Sweeney announced, after he undergoes a lumbar microdiscectomy scheduled for Thursday.

The surgery is to repair a lumbar spine disc herniation and will be performed by Dr. Louis Jenis at Massachusetts General Hospital.

Seidenberg, 34, is expected to make a full recovery.

“It’s definitely a setback, first and foremost, from Dennis’s standpoint,” Sweeney told reporters. “He’s worked hard. He came back from a [torn] ACL last year and has a setback, which we hope being identified fairly early in camp, trying to get some rest to let it calm down — wasn’t able to do that.

“So it’s definitely a setback. It’s obviously an opportunity for the other guys we were evaluating anyway amongst our D core, and we’ll go from there.”

Sweeney said that the Seidenberg sustained his injury during his own off-season training. The team was made aware on Monday.

“You know what? He apologized,” Sweeney said. “He’s a proud guy and a team member, and he takes that to heart. So he was apologetic, and said he’ll do what he can to get back, and that’s what you appreciate in a guy who cares.”

The Bruins’ blue line has been hampered in the last year by injuries and trades, but Seidenberg was a constant. He played all 82 games for Boston in 2014-15, scoring 14 points.

Seidenberg’s injury could open up a chance for young defencemen such as Colin Miller or Joe Morrow to crack the Bruins’ opening-night roster.