The Massachusetts-born defender is amidst the worst season of his NHL career, and it couldn’t come at a tougher time. Regarded as a high-end, complementary top-four defender with exquisite possession numbers since becoming a full-time big-leaguer in 2018, Grzelcyk is now in the final season of a four-year, $14.75M contract and will be an unrestricted free agent next summer. Unfortunately, his game has cratered this year, posting just one goal and a -3 rating in 20 contests. He is averaging 17:04 per game, his lowest usage since averaging 16:44 per game in his rookie season in 2017-18. When healthy, he’s been stapled to a pairing with Charlie McAvoy this season, which has been the Bruins’ highest-event pairing at both ends of the rink. Grzelcyk’s -3 rating and 48% Corsi share at even strength are both career lows.

With Grzelcyk out of the lineup, rookie Mason Lohrei will skate on a pairing with McAvoy in tonight’s game against the Jets. Across multiple stints on the Bruins’ NHL roster this season, the 22-year-old Lohrei has two goals, three assists, and a -4 rating through his first 15 NHL games and is averaging 16:59 per contest.

Elsewhere in the Eastern Conference as the Christmas weekend draws near:

Panthers center Anton Lundell will be activated off injured reserve before tomorrow’s game against the Golden Knights as he “should be” ready to return from an illness, head coach Paul Maurice said Friday (via Panthers senior digital content manager Jameson Olive). Lundell was close to returning for last night’s 4-1 loss to the Blues but could not play. The 22-year-old has missed the last four games with an undisclosed illness that was serious enough to warrant an injured reserve placement, opening up a roster spot. The Panthers have an active roster of 22 players, so they won’t need to make a corresponding transaction to make room for Lundell once the holiday roster freeze lifts on December 28. Through 28 games, the third-year two-way center has two goals and ten assists for 12 points.

The Islanders will remain without three regular defensemen in the lineup against the Hurricanes tomorrow as Scott Mayfield, Adam Pelech and Ryan Pulock did not travel with the team, Andrew Gross of Newsday reports. Mayfield has missed the last five games with an upper-body injury and remains on injured reserve, although he’s eligible to be activated at any time. It’s unclear whether the veteran shutdown man will be ready to go for the Islanders’ first game after the holiday break, a home tilt against the Penguins next Wednesday. Pelech, 29, is on long-term injured reserve and, while he’s been out long enough to be activated at any time, has yet to resume skating and has no timeline for a return from an upper-body injury that’s kept him out since American Thanksgiving. Pulock is also on injured reserve and last played on December 7 against the Blue Jackets, missing the subsequent seven games with a lower-body injury. He has also yet to resume skating with the team and does not appear close to a return. The Islanders have gone 2-1-2 in their last five games without half of their regular defense corps.