MONTREAL -- The good news is that Marco Di Vaio, the Impact's top scorer last season, has served his three game suspension and will finally be back with his Montreal teammates to try to turn their fortunes around Saturday in Philadelphia.

The bad news is that the Impact will fall to 0-4 on the season with another loss.

But the gloom of starting the season with three straight defeats hasn't descended on the Montreal Impact just yet.

The players and their new, as-yet winless coach Frank Klopas, were upbeat this week as they prepared to face the Union on Saturday in Philadelphia.

"The effort and intensity have been very good," said Klopas. "Everybody's shown they're ready to play. Those setbacks will go away if we keep working like we have been."

There is reason for optimism, starting with the return of star forward Marco Di Vaio and midfielder Andres Romero from the three-game suspensions they incurred from a scuffle at the end of their playoff game in October in Houston.

The 38-year-old Di Vaio, a 20-goal scorer last season, may help them end a goalless string that has reached 205 minutes after being shut out in their last two matches.

"He's a competitive person, but it's for the right reasons -- for the group," Klopas said of Di Vaio. "His ability to create, and wanting ball in difficult moments, and to score goals... don't mean anything to him unless it helps the team win."

Di Vaio is likely to step in for Andrew Wenger, who had a goal in a season-opening 3-2 loss in Dallas while filling in as the lone forward. It was not clear if Romero would start in his usual left midfield position or be available off the bench.

There were also reports this week that the club is close to signing a third designated player to go with the Italian Di Vaio and Argentine midfielder Hernan Bernarello.

Ignacio Piatti, an attacking midfielder who usually plays on the left wing, is believed ready to ink a deal that would see him join the Impact in June from the San Lorenzo club in Argentina.

The team that opened camp with no significant signings, despite a late season plummet from first to fifth place last season, looks ready to make some changes.

They also added fullback Heath Pearce during camp. A former Major League Soccer all-star with the New York Red Bulls who is coming off hip surgery, Pearce saw his first game action off the bench in a 2-0 loss at home last week to the Seattle Sounders.

"I feel healthy and fit," the 29-year-old Pearce said. "It's been a long process. I feel young again."

It was uncertain if he will start at left back, where the team's first round pick in this year's draft, Eric Miller, has been impressive.

Pearce likes how the Impact have not hung their heads despite the losses. The team started the 2013 campaign with four straight wins.

"I don't think there's cause for alarm right now based on our results," he said. "I've been in situations before where seasons didn't start well and I've see a complete change in attitude and things get really dark and negative, but here it's been upbeat."

Defence has been an issue as Montreal has conceded six goals while scoring only twice.

They have been lively on attack, leading the league with 57 shot attempts and 20 on target, but aging centreback Matteo Ferrari and converted fullback Hassoun Camera have been overwhelmed at times on counterattacks and set pieces.

The Impact are missing centre back Adrian Lopez, who is due to resume practising soon after knee surgery, and the oft-injured Nelson Rivas.

They hope to fix their defensive problems against Philadelphia. Montreal is 3-1-1 with 10 goals against the Union scored since joining MLS in 2012.

The Union (1-1-1), coming off a 2-1 loss in Columbus, made major off-season changes including the addition of American midfielder Maurice Edu and midfielders Vincent Noguiera and Cristian Maidana.

But they also have injury issues on defence, with converted forward Aaron Wheeler now playing in the middle.

Impact goalkeeper Troy Perkins said the Union are a puzzle.

"With the players they have, especially the new players they've added, you don't know what you'll get," he said. "You don't know if they'll be a high press team or if they'll sit back and counter or if they'll try to play possession.

"So you just have to go in and play your game and make them adapt to you."

The Impact start the season with three of four games on the road, but after Philadelphia they will be back at Olympic Stadium for their next two against New York and Chicago.

Note -- The Impact have loaned 20-year-old midfielder Zakaria Messoudi to the Ottawa Fury of the NASL. The former Canada u20 player is a product of the Impact's academy.

-With a file from The Canadian Press