MONTREAL -- The Montreal Impact return to their real home hoping to turn around what has been a dismal start to the Major League Soccer season.

After going 0-1-2 in their first three home games indoors at Olympic Stadium, the Impact move into open air on the grass field at 20,801-seat Saputo Stadium to face the Philadelphia Union on Saturday afternoon.

"Olympic Stadium is great but it's a different environment in here," coach Frank Klopas said this week. "The fans are right on top of you. The players are looking forward to feeling that energy. And to being on grass, for sure."

Fans have been getting antsy on social media over the failure of the Impact (0-4-3) to win a game under newcomer Klopas so far this season, but the Union may be their best hope for a breakthrough.

They were 3-0-0 at home against Philadelphia in their first two MLS seasons, and the Union (1-2-5) have had nearly as much trouble winning games this season. Philadelphia is coming off a 2-1 loss in New York and a 0-0 draw at home with Houston in the past week.

Montreal paid a disastrous visit to Kansas City last week that started with an own goal off a throw-in and ended in a 4-0 defeat.

"Every game is another opportunity for us," said Klopas. "There's nothing we can do about the past, but we can do something about what's in front of us.

"The training sessions have been sharp. Everyone's committed."

The Impact's first reaction to a bad start came after a 1-1 draw in Philadelphia on March 29 when they sent 2012 first overall draft pick Andrew Wenger to the Union for scoring ace Jack McInerney in a swap of forwards.

Wenger and the player known as Jack Mac will face each other in their new colours for the first time.

"You always want to prove something," Wenger told the league website this week. "I think it was a rough time in Montreal for me personally. It clearly didn't go the way I would have planned it, but then, nothing ever goes to plan."

Wenger and McInerney each scored a goal in his debut for his new team, but the two have been shut out since. Wenger started the first three games of the season in Montreal while Marco Di Vaio was serving a suspension, but otherwise was used sparingly in his two-plus seasons with the Impact.

He has been a starter for the Union since the trade and is trying to find chemistry with forward partner Conor Casey, just as McInerney is learning to work with Di Vaio.

"I don't think it will be more of an incentive for Jack to perform well," said Klopas. "He's a competitive kid that he's a winner and he wants to do well whenever he steps on the field."

The Union will have to watch out for Di Vaio, who has five career goals against them.

The 37-year-old former Bologna striker said he has been on teams that started seasons slowly before and is confident the Impact can turn the campaign around. Although they are winless, they are only five points out of a playoff spot as the entire Eastern Conference seems to be tying as many or more games than they win.

A couple of victories would put Montreal back in the race.

"It's not easy because when (a slump) happens like this, it puts a lot of questions in your head and you don't know what you're going to do," said Di Vaio. "But I see the attitude of the players and the coaching staff is good.

"We work very hard every day. We have to believe in ourselves and our coach and then we're finally going to win."

Di Vaio and midfielder Justin Mapp were banged up in Kansas City but both were on the field this week and look ready to play.

A question is what Klopas will do with his struggling back line. Last week, he started youngsters Eric Miller, Karl Ouimette and Maxim Tissot along with veteran centreback Matteo Ferrari. He may opt to go with veterans Heath Pearce and Hassoun Camara.

"The coach is smart -- he sees things," said Ferrari. "He's trying to change the back line.

"From the first game, he changed a lot of players. I'm the only one he didn't change, so maybe next time is my turn. But anyway, I'm sure we'll find the right back line and keep it. Karl, for example, played well the last two games."

The Impact has been without injured centre backs Nelson Rivas and Adrian Lopez since the start of the season. Only Lopez looks close to returning from a serious knee injury, and he is likely a couple of weeks away.

There will be pressure on Klopas, who got a vote of confidence from sporting director Nick De Santis this week amidst calls from some fans for his job. Another setback won't go over well.

De Santis said it will take time for the team to adjust to its new coach, who is Montreal's third in as many seasons after Jesse Marsch and Marco Schallibaum were each fired after one season.

"I think we made decisions the last two years that we could easily not have made, either with Jesse or Marco," said De Santis. "I think that's because we wanted the club to move forward with Frank and his staff.

"The way they work, and the way I see the team react to him, I'm confident we'll come out of this."