The Sabres announced that Kaleta had surgery on Monday, before Buffalo's game at Boston. He was hurt during a 4-2 loss to Ottawa on Friday, and missed Buffalo's 7-1 win over Tampa Bay on Saturday.
Kaleta has 15 points (10 goals and five assists) and 87 penalty minutes in 54 games this season. The Northeast Division-leading Sabres (41-23-10) have already clinched a playoff berth.
After playing the Bruins, they have seven games left in the regular season, closing at New Jersey on April 11.