TIME: Tuesday, 7:30 p.m. EDT.
Thornton returned to Boston from the team's trip to get treatment for his back after he missed the final five minutes of the Bruins' 4-2 win over Tampa Bay last Monday.
He didn't play Thursday as Boston extended its winning streak to three games with a 5-2 victory over Florida, and also sat on Saturday when the Bruins suffered their worst defeat of the season.
Boston's Andrew Raycroft was pulled 13 minutes into the second period after allowing four goals on 24 shots, and the Bruins went on to lose 5-1 to unbeaten Ottawa.
Boston coach Mike Sullivan said he made the switch to try and add some jump to his team.
"Things weren't going our way and it certainly wasn't a reflection of (Raycroft's) performance," Sullivan said. "I thought we just needed a boost. I thought (backup goalie Hannu Toivonen) did pretty well to be thrown into the fire like that, and against Ottawa who is one of the hottest teams in the league."
Thornton said he is improving, and hopes to return for either this game or Thursday's contest in Boston against Buffalo.
Montreal has dropped two of its last three after opening the season with three straight wins on the road. The Canadiens fell to 0-2 at home with a 3-2 loss to Toronto on Saturday.
Canadiens rookie Tomas Plekanec scored his first NHL goal 5:33 into the third period to tie it at 2 before the Maple Leafs scored the winning goal at 12:16.
"It was a nice goal by Plekanec and then we tried to hang on so that we'd be able to come back," said center Mike Ribeiro, who assisted on the score.
Boston is 2-0-1 in its last three visits to Montreal.
STANDINGS: Bruins - 6 points, 5th place, 4 PB, Northeast Division. Canadiens - 8 points, 2nd place (tied), 2 PB, Northeast Division.
TEAM LEADERS: Bruins - Glen Murray, 4 goals and 8 points; Murray, Thornton and Sergei Samsonov, 4 assists; Hal Gill, 19 PIM. Canadiens - Michael Ryder, 3 goals; Alexei Kovalev, 5 assists and 6 points; Sheldon Souray and Pierre Dagenais, 12 PIM.
SPECIAL TEAMS (through Oct. 16): Bruins - Power play: 15.1 percent (5 for 33), 16th in NHL. Penalty killing: 85.3 percent (35 for 41), 15th. Canadiens - Power play: 13.1 percent (5 for 38), 22nd. Penalty killing: 87.5 percent (35 for 40), 10th.
GOALTENDERS: Bruins - Raycroft (2-3-0, 3.08 GAA); Toivonen (1-0-0, 4.77). Canadiens - Jose Theodore (3-2-0, 3.01); Yann Danis (1-0-0, 1 SO, 0.00).
SEASON SERIES: Canadiens, 1-0.
LAST MEETING: Oct. 5; Canadiens, 2-1. At Boston, Ryder backhanded in the rebound of Kovalev's shot on a power play with 11.1 seconds remaining to give the Canadiens the win.
ROAD/HOME RECORDS: Bruins - 3-2-0 on the road; Canadiens - 0-2-0 at home.