Matt Duchene and Bobby Ryan each had a goal and two assists for the Senators. Tkachuk and Colin White had a goal and an assist. Mark Stone also scored, and Craig Anderson stopped 24 shots.

Ottawa Senators defenceman Mark Borowiecki has been suspended for the second time in less than a week.

David Pastrnak led the way for the Boston Bruins with two goals and two assists, while Thomas Chabot scored the only goal for the Ottawa Senators on Tuesday night.

The Ottawa Senators will be missing three key players for their Saturday matinee against the visiting Los Angeles Kings.

Forwards Mark Stone and Matt Duchene will serve as alternate captains, while defenceman Mark Borowiecki and forward Zack Smith will alternate wearing an 'A' on the road and home respectively.

Tkachuk, the No. 4 overall pick in this year's NHL draft, is nursing an undisclosed injury.

A deal has been rumoured for months after Karlsson did not sign an extension offer from the Senators over the summer. The move comes on the eve of the first on-ice session at Senators training camp.

Duchene, who took part in an informal scrimmage with several of his Senators teammates Monday, says he sees plenty of reason for optimism heading into a new campaign – despite all the negative headlines about the team in recent months.

The Karlssons said the mission of the new charity, called "Can't Dim My Light," is to raise awareness about the effects that both bullying and cyber bullying that have on youth and to "promote inclusion and compassion."