Ottawa Senators defenseman Erik Karlsson will not play against the Boston Bruins at TD Garden on Thursday (7 p.m. ET; NBCSN, NESN, RDS, TSN5, NHL.TV) because of a lower-body injury, coach Guy Boucher said.

The Senators (42-27-10) will clinch a berth in the Stanley Cup Playoffs with one point against the Bruins or losses by the Tampa Bay Lightning and New York Islanders.

Karlsson, Ottawa's captain, missed games against the Minnesota Wild on March 30 and the Winnipeg Jets on April 1 with a lower-body injury, but returned for a home-and-home series against the Detroit Red Wings on Monday and Tuesday. He leads the Senators with 71 points (17 goals, 54 assists), and is fourth in the NHL in average ice time at 26:50 per game.