The Boston Bruins say veteran defenseman Dennis Seidenberg is lost for the rest of the season with torn ACL/MCL in his right knee. Among all of the injuries the B's have suffered so far this season, this one may be the most costly.

Only Zdeno Chara spent more time on the ice than Seidenberg. He is a major physical force on the blue line and it could put the Bruins in the trade market for some help.

Some of the young defenseman have played well but his veteran leadership cannot be replaced. He has played in 615 NHL games.

Seidenberg hurt the knee in the final minutes of Friday night's win over Ottawa.

The Bruins have called up Zach Trotman from Providence.

GM Peter Chiarelli says recovery time for Seidenberg is about eight months.