Boston, MA (SportsNetwork.com) - Boston Bruins forward David Krejci is expected to miss anywhere from 4-to-6 weeks after being diagnosed with a partially torn medial collateral ligament in his left knee.

Krejci left Friday's 5-1 loss to the Blues and did not return after an open- ice collision with St. Louis forward Alex Steen.

The 28-year-old center has struggled to seven goals and 19 assists over 38 games this season.

His loss for a significant chunk of the rest of the regular season is not a good sign for the Bruins, who have gone 2-5-2 in February and are in danger of falling out of the Eastern Conference playoff picture.