07/12/2013 04:43 EDT | Updated 09/11/2013 05:12 EDT

Impact look to stay on top as tough MLS stretch begins against Red Bulls

MONTREAL - Now comes the tough part for the Montreal Impact.

After picking up only two of a possible nine points against lower-ranked teams, the MLS Eastern Conference leaders begin a series of three matches against top contenders when they visit the New York Red Bulls on Saturday night.

Montreal (9-4-4) finished the first half of the 34-game regular season with the league's best record, but that is about to be tested. After New York, they have home games against Dallas and Kansas City, who are currently in second spot in their respective conferences.

"They're good teams," goalkeeper Troy Perkins said this week. "It'll be a gut-check for us, to see where we're really at and see how badly we really want to win in this league and how far we really want to go."

The Impact have games in hand over all their closest rivals, but they let a chance to take a stranglehold on first place slip away with a 4-3 loss at home to Colorado followed by draws of 3-3 in Toronto and 1-1 at home to Chivas USA.

It's hard to call a 0-1-2 skid a slump, but they will need to be better, especially on defence, to stay on top against clubs like third-place New York (8-7-4). The Red Bulls have played two more games but could tie the Impact's 31 points with a win.

"In this league, it's impossible to stay on a roll the whole year," added Perkins. "You're going to have valleys.

"There's so much parity in this league that anyone can beat anyone. It's not like the EPL or the Bundesliga where there's four teams that run the show every year. So we have to find our feet and start grinding out results again."

The Impact should have midfielder Justin Mapp back from a leg injury to boost an attack led by forwards Marco Di Vaio, the co-leader in MLS goal-scoring with 11, and Daniele Paponi.

The Red Bulls are having troubles of their own, with one win and four losses in their last five matches. They fell 2-0 at Colorado in their last outing on July 4.

This week, 37-year-old Juninho decided to return to Brazil after only 13 games with New York, but they still have a potentially lethal attack led by Thierry Henry and Fabian Espindola.

And Australian international Tim Cahill looks to be back on track with four goals in his last eight games.

"It's about trying to get it right this week," Cahill told his team's website. "These are the big games you want to play. A result against them would be pretty special."

"Although they didn't win for a while, they're a difficult team to beat," added Henry, who has six goals in five career games against Montreal. "They can be behind and come back in it."

That's what happened the last time they met on May 8, as the Red Bulls took a lead on two Henry goals before Montreal answered with a late strike from Di Vaio. The Italian, who turns 37 on Monday, nearly tied it at the end when he put a shot off both goalposts.

The Impact defeated New York 1-0 in March at Olympic Stadium.

"Our attitude's the same, the only thing I see is maybe we need to start worrying about ourselves more instead of focusing on the big picture," added Perkins. "Start worrying about what we have to do on the pitch and stop worrying about results."

Coach Marco Schallibaum said the team put out a better defensive effort against Chivas while still generating most of the scoring chances against a team that elected to stay back and defend.

There is more back-and-forth play when they face New York, which made for entertaining soccer in their first two meetings.

"We've been a little bit unlucky these last three games and we didn't play like we normally play, but during a season, that can happen," said midfielder Felipe Martins. "The important thing is that we get back to doing what we did before. No panic."

Schallibaum does not announce his starting 11, but he is expected to go with the usual back line of Matteo Ferrari and Alessandro Nesta flanked by Jeb Brovsky and Hassoun Camara, who has two goals in his last three games.

Other than Felipe and Patrice Bernier, the midfield is up in the air, as captain Davy Arnaud will likely be ready to play after being rested for a game. Arnaud recently returned from a concussion.

Sanna Nyassi was perhaps Montreal's best player against Chivas and may have earned another start while Mapp, Andres Romero, Andrea Pisanu and Collen Warner are available.

Most of talk this week was about how well the team did in the first half of the season, but now comes the tougher job of staying on top.

"We're happy with where we're at, but now it's time to turn on the after-burners," said Brovsky.

The Impact should get a notion of what the front office is up to when team president Joey Saputo holds a news conference on Monday.

There may be news on the future of injured central defender Nelson Rivas, who has yet to play this season, or of potential new signings. Sporting director Nick De Santis is looking for a creative attacking player and depth in the central defence now that the transfer window is open.