Hnidy joined the Bruins on the ice in Vancouver on Wednesday. He has yet to be cleared to play by doctors and wasn't in the Boston lineup against the host Canucks on Saturday night.
The 35-year-old Hnidy -- who spent two seasons with the Bruins in 2007-08 and 2008-09 -- hasn't played since last season, when he suited up for the Minnesota Wild. He tore his rotator cuff in the Phoenix Coyotes'
training camp last fall.
Hnidy has 16 goals, 71 points and 631 penalty minutes in 547 NHL games with six teams over nine seasons.
The Bruins also signed minor league forward Kirk MacDonald, who was playing on an AHL contract this season. He will remain with the Bruins' AHL Providence affiliate.
James Murphy covers the Bruins for ESPNBoston.com. Information from The Associated Press was used in this report.