Ottawa Senators Patrick Eaves celebrates his assist on a goal against Montreal Canadiens goalie Cristobal Huet in the second period. (CP/Ian Barrett)
Plekanec had two assists and linemates Alex Kovalev and Sergei Samsonov did the scoring as the Canadiens got three third-period goals in a 6-5 comeback win over the Ottawa Senators on Saturday night.
Ribeiro was traded just before the game to the Dallas Stars for defenceman Janne Niinimaa.
"I don't know if I'll play on that line all the time, but I'm happy to play with those guys," said Plekanec. "We'll see how long it goes like that."
Trailing 5-3 going into the final period, Kovalev scored on a rush down the left side at 3:51, Samsonov banged in Andrei Markov's pass at 15:16 and Kovalev had the sell-out crowd of 21,273 on its feet as he got the game-winner with 1:52 left to play.
Plekanec's drop pass to Kovalev for a spin-around backhand from the slot produced the winning goal.
"They were good tonight," said coach Guy Carbonneau. "I tried that experiment in an earlier game and after Mike was gone, we decided that that's how we'll go.
"It's a matter of putting the right people together."
The win left Montreal at 3-5 and Ottawa at 5-4 as both clubs completed their pre-season schedules.
Mike Johnson, Michael Ryder and Sheldon Souray also scored for the Canadiens, who were beaten 5-2 in Ottawa Thursday night.
Dany Heatley, his fifth of the pre-season, and Andrej Meszaros both scored in the first frame, while Peter Schaefer, Cristoph Schubert and Chris Neal had goals in the second for Ottawa.
The Sens scored 34 goals in nine pre-season games, best in the Eastern Conference.
"Our offence is always going to be there for us," said Heatley. "We have a lot of guys who can put it in the net and we have a lot of speed.
"For us, it's a matter of bearing down and really burying teams like we did last year."
Montreal outshot Ottawa 30-25 and neither the Canadiens' Cristobal Huet nor Ottawa's Martin Gerber was sharp in goal.
The Canadiens needed help on defence with Francis Bouillon and Jean-Philippe Cote out with injuries, so they reached out for Niinimaa, a 10-year veteran coming off ankle surgery.
Montreal was deep at centre and felt it could afford to move Ribeiro.
"The only difference is that Tomas skates a little better than Mike," said Carbonneau.
Carbonneau returned to Montreal last January from Dallas, just before the Stars acquired Niinimaa from the New York Islanders.
"Mike's going to a good organization in a good city and the style in the Western Conference may be better for him than in the East," said Carbonneau. "I know from being there last year that Mike's name was being mentioned."
After Johnson tapped in Radek Bonk's rebound 2:13 into the game, Ottawa scored on two of its first three shots on Huet as Heatley shot into an open side at 5:08 and Meszaros scored on a point shot 35 seconds later.
Ryder tied it at 7:52 on a backhand shot from the slot.
Schaefer and Souray exchanged goals early in the second frame and Schubert put Ottawa ahead on a power play at 5:27 on a low shot from the blue line.
Neil got his fourth of the pre-season at 6:22 when he pushed a loose puck on a rush past Huet.
The Senators killed off a two-man Montreal advantage for 1:23 midway through the final period.
Niinimaa is to join the Canadiens Sunday night in Mont-Tremblant, Que., where the team will make its final preparations before starting the regular season Friday night in Buffalo.