The Boston Bruins have made a number of roster moves on their defense, amid multiple major losses on the blue line.
Bruins GM Don Sweeney announced Wednesday that Matt Grzelcyk is going on long-term injured reserve. This means that the B’s expect Grzelcyk to miss at least 10 games or 24 days. The earliest he’d be able to return to the Bruins would be Saturday, Nov. 25, when they take on the New York Rangers at Madison Square Garden.
Coupled with Charlie McAvoy’s 4-game suspension, the Bruins will be without their top defensive pairing for more than a week, and will have to replace Grzelcyk for longer than that.
There’s a silver lining to the Grzelcyk injury: the Bruins are giving 22-year-old defenseman Mason Lohrei the call-up to Boston as one of their corresponding moves.

Oct. 3, 2023; Boston, Massachusetts, USA; Boston Bruins defenseman Mason Lohrei (6) gets set for a face-off during overtime against the Washington Capitals at TD Garden. Mandatory Credit: Bob DeChiara-USA TODAY Sports
Lohrei has tallied four assists in seven games with Providence so far. P-Bruins broadcaster David Maher described Lohrei’s most recent work as “his best game of the season so far.”
There’s a big opportunity ahead for Lohrei, who appears poised to officially make his NHL debut in the coming days and weeks. Originally a second-round pick to Boston in 2020, Lohrei has long been the Bruins’ best defensive prospect and a potential future building block on the left side.
However, it’s not guaranteed that Lohrei plays a ton after his call-up, for a number of reasons. One is that the Bruins made other roster moves, which we’ll detail below…