Both teams hope to end a lengthy winless streak when they clash on Saturday night at Saputo Stadium.
The Impact (9-5-4) have two draws and a pair of defeats in their last four games, but Dallas (8-5-7) tops that by going winless in six straight Major League Soccer matches — and seven overall if you count a loss to Portland in U.S. Open Cup play.
Montreal's latest setback was a 4-0 thumping on the road to the New York Red Bulls last weekend, which knocked them out of first place in the Eastern Conference.
"It's true it was a bad game, we can't hide that," fullback Hassoun Camara said this week. "It wasn't good on any level.
"We know we have to work hard and talk together on that. It has to be an alert for the rest of the season. We have a good team, good players and we know we can answer back on Saturday."
In their last four outings, the Impact blew leads twice in the second half to fall 4-3 at home to Colorado, drew 3-3 in Toronto, tied lowly Chivas USA 1-1 at home and then were spanked by the Red Bulls.
A defence that had previously been solid surrendered 12 goals in the four games.
Still, team owner and president Joey Saputo gave his team a passing mark in his mid-season assessment for taking a big step forward from the club's expansion season in 2012, when they finished seventh in the conference and out of the playoffs.
They now sit in second place only two points out of top spot, with games in hand on all their closest rivals.
They hope it is simply a slump, a rough patch like nearly every team has at some point in a campaign.
"It's only normal," said sporting director Nick De Santis. "Sitting in first place is the hardest thing to do and we've been there for quite a while.
"At the beginning of the season, we felt we had a lot to prove because we underachieved last year. There was a lot of pride at stake (this season) and it showed game in, game out. We were able to get results not only out of good play, but out of character and pride and really sticking to our identity.
"Once we got to first place, it felt as if we've proven to everyone that we're a good team. To stay there is a lot more difficult. And it makes us realize as well that maybe we're not ready to be in first place yet. Now, how good are we to get out of this as soon as possible?"
Coach Marco Schallibaum said some players were struggling to adapt to the summer heat, so there may be lineup changes for Dallas. Midfielder Andres Romero was substituted in the first half in New York by hard-working youngster Blake Smith, who may have earned a start.
And forward Marco Di Vaio returned home to Italy to attend to a family matter this week and may not be ready to play, handing the role of primary striker to his former Bologna teammate Daniele Paponi.
Whether there will be changes no defence was not certain. The back line of Alessandro Nesta and Matteo Ferrari flanked by Camara and Jeb Brovsky has taken heat in the media of late.
But not from De Santis.
"Since we've taken a lot of goals, everyone questions the defence, but if you look at the games, it's not only the defence," he said. "Look at our midfield, which isn't as good as it was a few weeks ago, and the mentality of the team and how it's a little bit fragile, and how it's easy at times to score on us.
"We're looking at every angle. Nesta and Ferrari playing game after game gets difficult, but I think there are solutions within the roster to fix that."
Dallas also has concerns after being outscored 5-0 in its last three games, including a 3-0 loss at home last week to Salt Lake.
They will be boosted by the return of central defender George John, who missed four games with a hamstring injury.
Dallas has not won since June 12, but John would not call the Montreal encounter a must-win game.
"I try to stay away from extremes," he told the team's website. "Obviously, we're going through a rough stretch, a seven-game winless streak, so it's important that we win soon.
"But I don't think you're ever facing a must-win unless you're in the playoffs or battling at the end of the season to make the playoffs. You always want to win, but when you put expectations like that on, it puts unnecessary pressure on you."
John made headlines in April when he was hit in the head by a beer bottle apparently thrown by one of the team's own fans after scoring a game-winning goal against Los Angeles.
This week, Dallas signed 22-year-old Argentine Mauro Diaz from Argentine club River Plate and he may see action in Montreal.