It always has to concern the Bruins when a Northeast Division rival makes a trade to bolster itself, let alone when that team is Montreal.

Today the Canadiens swung a trade for New York Islanders blueliner James Wisniewski in a move that not only aids the Habs’ back end but also makes the market for trade-bait defensemen a little thinner.

Just a couple weeks ago, I documented the potential trades for defensemen that might be available between now and the Feb. 28 trade deadline. Wisniewski made the list, and now he’s heading to Montreal, where he should be an upgrade on Alex Picard on the Habs’ third pair.

Wisniewski is a minus-18 this season playing for a dreadful Isles squad, but has recorded 21 points. Last season, he recorded a career-high 30 points while with Anaheim.

Wisniewski carries a cap hit of $3.25 million, according to CapGeek.com. So, of course, he would’ve been too rich for the Bruins without a move to cut salary first. The Canadiens on the other hand were able to get a deal done without touching their roster and just give the Islanders a second-round pick and a conditional fifth-rounder.

Look for Wisniewski to add both solid play and toughness to the Montreal defense corps. And if we’re lucky, he’ll learn some French-Canadian gestures to go along with this one he directed at Sean Avery earlier this season.