06/28/2013 03:42 EDT | Updated 08/28/2013 05:12 EDT

First-place Impact look to continue home dominance vs struggling Rapids

MONTREAL - On paper, the Colorado Rapids look like easy prey for the Montreal Impact.

But that is the kind of overconfidence the Impact are hoping to avoid when they face the struggling Rapids on Saturday night at Saputo Stadium.

Colorado, seventh in the MLS Western Conference at 5-7-5, has lost three games in a row and is up against the Eastern Conference leading Impact (9-3-2), who have yet to lose at home this season (6-0-1).

"You can't look at the standings because a team can wake up at any time," Montreal midfielder Patrice Bernier said. "But we're at home.

"We know how good we are. We have to keep that momentum. And if we want to keep it that way, we have to show no mercy."

The Rapids were on a 5-1-3 spurt in April and May before losing three in a row in June, when they were outscored 7-2. They are coming off a 3-0 loss in Portland.

The Impact, who shut out Houston 2-0 in their last outing June 19, are seeking a fifth straight win at home. They lead the conference with 16 goals at home, nine of them from striker Marco Di Vaio. The Italian has scored at least one goal in each home game this season.

"There's calm and confidence when we play at Saputo," added Bernier.

Montreal will have captain and midfielder Davy Arnaud back after missing nine games with a concussion, but it was uncertain if he would start.

Midfielders Justin Mapp (hamstring) and Sanna Nyassi (groin) are expected to sit out, but Montreal has extra depth this season with Andres Romero and Andrea Pisanu playing the outside positions.

The Rapids' attack is led by former Vancouver Whitecap Atiba Harris, who has four goals, and rookie Deshorn Brown, the sixth overall pick in this year's SuperDraft, who has three goals and four assists.

But Colorado is among the league's lowest-scoring teams with 17 goals in as many games.

Off-season acquisition Edson Buddle, a 19-goal scorer with Los Angeles in 2010, has only two while working his way back from injuries.

Coach Oscar Pareja lamented on the team's website this week a lack of finish at the net.

"We have to take advantage of our opportunities," he said. "Against Portland, we had many.

"We know we didn't defend well. Individually we have to be better and collectively, we have to defend better."

Pareja is looking for a response from his club in Montreal, which will be tough. The Impact are 3-0-1 against the West.

It is the only meeting between the clubs this season. A year ago, Montreal gave up a late goal in a 3-2 loss in Denver, but much has changed since then.

As an MLS expansion team in 2012, the Impact went 12-16-6 to finish seventh in the East.

After 14 games, they were 4-7-3 and had surrendered 21 goals. In the a same number of games this season, they are 14 points better and have scored eight more goals and allowed four fewer.

The Impact have a four-point lead over Philadelphia and New York, with games in hand on both.

"They say it's hard to get there and harder to stay there," assistant coach Mauro Biello said of being on top. "Teams are getting ready for us.

"They're coming here to try to beat us and steal points and we have to be ready for everything. Up to now we've done a good job."

The attack has centred on Di Vaio, who shares the league lead with 10 goals with Philadelphia's Jack McInerney and Chicago's Mike Magee. He has been especially dangerous when teamed up front with former Bologna teammate Daniele Paponi, who recently returned from a thigh injury.

Colorado has named central defender Drew More as captain to replace veteran Pablo Mastroeni, who was traded to Los Angeles last week.

Veteran goalie Matt Pickens is ready to return from a broken arm suffered three games in to the season, but the Rapids are expected to stay with back-up Clint Irwin in Montreal. Congolese forward Danny Mwanga got his U.S. citizenship on Monday.

After Colorado, the Impact have their second league meeting of the season with Toronto FC at BMO Field. The Impact beat TFC 2-1 at home on March 16 and then won a two-game Amway Canadian Championship series between the rivals.