Doull will lose $2,500 in salary.
Doull had to miss Boston's rematch against New York on Tuesday
The team did not yet have the results of the exam, but the Rangers' initial diagnosis was that Kasparaitis had sprained his MCL, a ligament that heals on its own and does not require surgery.
Also on Tuesday, the Bruins claimed center Craig MacDonald off waivers from the Florida Panthers, for whom he had no goals, three assists and 25 penalty minutes in 34 games this season. MacDonald, 26, has two goals and seven assists in 92 career games with the Panthers and Carolina Hurricanes.