The Bruins have signed defenseman Aaron Johnson to a one-year, two-way contract.
Johnson, 29, played 56 games for the Blue Jackets  last year, registering three goals and 16 assists for a career-best 19 points. He had a minus-12 rating.
Johnson has bounced around in the league since being drafted by Columbus in 2001, as he played in the Islanders, Blackhawks, Oilers, Predators and Flames organizations before returning to the Blue Jackets  last season.
The former third-round pick played the entire 2010-11 season in the AHL for the Milwaukee Admirals, notching nine goals and 26 assists for 35 points and 70 penalty minutes. He had a plus-10 rating in the AHL in 2010-11.
The fact that the Bruins have now signed a few fringe-NHL blueliners in Johnson, Garnet Exelby and brought back Matt Bartkowski without signing any true top-6 defensemen suggests that the team is indeed expecting Dougie Hamilton to make the team next season. Any one of the aforementioned three signings could serve as a seventh defenseman at the NHL  level.