In seventh place in the Eastern Conference, the Impact will need to run the table in the four games left in their regular season and hope that the Houston Dynamo, who hold the fifth and final playoff spot, and the sixth-place Columbus Crew both falter down the stretch.
It will be tough enough for Montreal (12-15-3) just to win their next game as they face the Eastern Conference leader, Sporting Kansas City (16-7-6), at a sold-out Saputo Stadium on Saturday afternoon.
A 2-0 victory over the Red Bulls in New York on Wednesday gave Kansas City a 5-0-2 record in their least seven games.
''They pressure teams for 90 minutes,'' said Impact captain Davy Arnaud, a former Kansas City skipper. ''Physically, they're very good. They can wear you down.
''Even though they played (on Wednesday) I don't expect them to be anything less than what they've shown recently. They want to get first place in the conference and try to win the Supporters Shield (first place overall). I think that's their goal now.''
The Impact raised their fans' hopes with a five-game winning run in August, but they lost their last two games on the road against conference rivals — 2-0 in Columbus and 3-1 last Saturday in Chicago — to fall to seven points out of a playoff position.
''We realize the situation in terms of the table right now, but in terms of our approach, it won't change,'' added Arnaud.
Kansas City will put one of the league's best road records (8-4-2) up against a Montreal squad that sports one of the top home marks (10-3-2).
The irony is that in their two meetings this season, Montreal and Sporting have each won in the other's stadium, with the Impact taking a 2-0 decision at Kansas City on May 5 and losing 3-1 at home on July 4.
''They've had success on the road because they press, they don't just sit back,'' said Montreal coach Jesse Marsch. ''We're ready to deal with that.
''We can also feel that even when they press we can open up space ourselves and play a bit. But on top of that, they're a team that's extremely dangerous on set pieces, so everything from long throw-ins to free kicks to corners will be a big determiner of the outcome.''
Montreal has not scored off a free kick this season while Kansas City has tallied five.
The Impact will be without oft-injured central defender Nelson Rivas, who had a flare-up of a lingering knee problem, but the club has become used to shuffling its back line.
The likely starters will be Italian veterans Alessandro Nesta and Matteo Ferrari in the middle, with Hassoun Camara on the left side and Jeb Brovsky on the right. Ferrari is a natural central defender who has looked like a fish out of water at fullback in recent games and will likely welcome the move.
''If you went through the season, there would be so may back lines and so any changes,'' said Marsch. ''The group has done well with the changes. Each guy stepped in and understood the role and done a good job. So I think these four will do well.''
They will also have midfielder Justin Mapp back in the lineup on the left side. The veteran came on as a substitute in Chicago in his first game since he injured a hamstring on Aug. 12. He does not expect to play a full match, and speedy Sanna Nyassi will likely be ready to go in from the bench.
''I feel good,'' Mapp said. ''I don't know about 90 minutes after being out for a while, but we have a deep team if I get fatigued.''
Striker Marco Di Vaio has scored one goal in each of the last four games and has five in his last six matches.
Forward Bernardo Corradi returned from Italy this week after having season-ending knee surgery. He told reporters he is not sure if he will be back next season.
Kansas City will be without midfielder Roger Espinoza, who is suspended one game for accumulating yellow cards. They are expected to move Graham Zusi into the middle behind striker C.J. Sapong.
It will be Montreal's last home game until they end the regular season at Saputo Stadium on Oct. 27 against New England. Their next two are on the road at Houston Oct. 6 and Toronto Oct. 20.Suggest a correction