The Boston Bruins admitted today that standout rookie defenseman Charlie McAvoy has a sprained MCL in his left knee and is out at least four weeks.

McAvoy injured the knee early in the game vs Montreal Saturday night. Until now, the team simply called it a 'lower body injury'.

GM Don Sweeney said today that a left MCL sprain and he will be re-evaluated in four weeks.

That means he's out of the lineup through at least the last week of the regular season. The B's last game is April 8th. Playoffs are expected to start around the 11th or 12th.

McAvoy is second on the team with time-on-ice (22:07 per game). He has seven goals and 25 assists.

The trade deadline deal to get veteran Nick Holden from the NY Rangers looms even larger now.

NOTE: The Bruins play the Detroit Red Wings tonight.