Bruins head coach Claude Julien said today that defenseman Johnny Boychuk has been diagnosed with a “mild” knee sprain. The coach classified Boychuk as “day-to-day.”

Boychuk was injured in a collision with Pittsburgh forward Arron Asham in the third period of the Boston loss at TD Garden Tuesday night. Boychuk is not with the team in Ottawa, where the Bruins will face the Senators tonight.