MONTREAL -- Marco Di Vaio won't be the only proven goal-scorer on the Montreal Impact any more.
Winless in four games to open the Major League Soccer season, the Impact (0-3-1) sent 2012 first-overall draft pick Andrew Wenger to the Philadelphia Union for all-star Jack McInerney in a swap of forwards on Friday.
The surprise move came a day ahead of the Impact's home game against another team searching for its first victory -- the New York Red Bulls (0-1-3).
The 20,000-plus fans expected at Olympic Stadium on Saturday won't get to see the player known as Jack Mac however, as 21-year-old McInerney only begins training with his new team early next week.
The 23-year-old Wenger would not have been available anyway, as he is serving a one-game suspension for drawing a red card in Montreal's 1-1 tie at Philadelphia last weekend. He will miss the Union's game at Chicago.
Wenger was the top pick in the SuperDraft when Montreal entered MLS in 2012, but has struggled to find regular playing time.
Impact president Joey Saputo tweeted: "Thank you Andrew. You will always be part of our history."
When McInerney is ready to play, coach Frank Klopas will decide whether to have him and Di Vaio on the field at once or alternate them in the one-forward system the team usually employs.
"I'm excited to play under his wing," McInerney said of Di Vaio. "He's one of the best finishers MLS has ever had.
"I don't know how it will play out on the field, but if we play together it's a dream come true. Whether we play together or not, it's a great learning experience."
The Chattanooga, Tenn., native is in his fifth MLS season. Drafted seventh overall by the Union in 2010, he has a goal and an assist in four games this season and 25 goals and four assists in 95 career MLS games.
McInerney had 10 goals in the opening 15 games in 2013, which earned him a chance to have Di Vaio as a teammate for a day at the all-star game.
However, the five-foot-10 striker added only two more after returning from more than a month with the U.S. national team at the CONCACAF Gold Cup, where he didn't play and was released after the group stage.
He said the inactivity affected his rhythm and his confidence.
"My confidence was down and at the same time the team wasn't doing well and that's why it didn't go well for me," he said.
He said he was surprised to be traded, but was excited to join the Impact.
The Union opted to deal away a player whose contract is up at the end of this season and who was expected to seek a raise. The 2014 salary list is not out yet, but he earned $125,500 last season.
McInerney has talked about moving to Europe, but said he would consider signing a new deal with Montreal.
Impact sporting director Nick De Santis said McInerney has an option year on his contract and should be with the Impact until the end of the 2015 season.
In return, Philadelphia got the six-foot 185-pound Wenger, a native of Lancaster, Pa., who moves back to his home state to pursue his bid to be an regular MLS starter.
"Andrew is a young and talented attacking player who we think is a good fit with our style of play," Union coach John Hackworth said.
Wenger, a converted defender, has six goals and three assists in 51 career games.
He started the first three games this season while Di Vaio sat out a suspension and had one goal -- a header in a season-opening 3-2 loss in Dallas.
Di Vaio's importance to the Impact was underlined when he returned last Saturday. Only four minutes after Wenger was sent off, the Italian put a clinical finish on a feed from Justin Mapp to tie the game in the 80th minute give Montreal its first point of the season.
There has been concern that the club was too dependant on their 37-year-old striker, so McInerney will give them another option. He and Di Vaio are similar players -- opportunistic, smaller forwards who let their teammates know about it when they don't get the ball.
And Di Vaio is expected to retire at the end of the season.
"It's important that you have not only one striker that is able to score goals," said De Santis. "We don't depend just on Marco, but he's scored so many goals and taken a lot of the load.
"We get a quality player in Jack who has proven he can score goals at a young age. He gives us more firepower up front."
It was the Impact's biggest trade since they sent former all-star goalkeeper Donovan Ricketts to Portland for Troy Perkins on Aug. 7, 2012.
The move came as the Impact try to get back on course after a weak start.
Four of their next five games are at home. Klopas' former club, the Chicago Fire, visits Olympic Stadium next week, and the Impact's first game on the grass pitch at Saputo Stadium is April 26 against the Union, followed by a May 10 meeting with Kansas City.
"It's an opportunity to gain some ground," said Klopas.
The Red Bulls are hurting, with forward Tim Cahill (hamstring) and right back Richard Eckersley (ankle) going down in a 1-1 home draw with Chivas USA last week.
Also, it was unknown if star forward Thierry Henry or centre back Jameson Olave will play because both often sit out games on artificial turf.
It is expected that Impact captain Patrice Bernier and fullback Jeb Brovsky, both regaining fitness after injuries, will start from the bench for a second week in a row. Former Red Bulls left back Heath Pearce will likely get a second straight start.