"They're going to have to replace the nets biweekly in Montreal," he tweeted. "DiVaio and Jack Attack shooting at the same goal at the same time? Oh no."
Marco Di Vaio and the striker known as Jack Mac will be shooting at Magee's Chicago goal if coach Frank Klopas elects to use them as a forward tandem when the Impact play host to the Fire on Saturday at Olympic Stadium.
So far, there has been no word on how McInerney will be used in his Impact debut, but it's unlikely they acquired him to warm the bench until the 37-year-old Di Vaio needs a rest.
Most likely, Di Vaio and McInerney will play together in what could become one of the league's most dangerous partnerships. Last season, Di Vaio scored 20 goals, while Jack Mac had 12 for the Union.
"We could play them together," Klopas said Tuesday after McInerney's first practice with his new team. "We'll see through the week.
"That's the reason we have him here. I think they can play together, but there's stuff we have to do in training this week."
Klopas, a former Chicago player and coach, will be looking for his first Impact (0-3-2) win against his old team.
The Impact sent 2012 first overall draft pick Andrew Wenger to Philadelphia for McInerney on Friday, but neither played for his new team on the weekend.
McInerney, a fifth-year MLS veteran despite being only 21, arrived on Monday looking for a fresh start with Montreal.
"I'm pretty similar to Di Vaio, just with movement and scoring goals," said McInerney. "I hope I'm on the field.
"I don't want to come in and just sit on the bench. Training this week is going to help. I don't know what's going to happen in the future — starting or coming off the bench — but I just want to make an impact."
Reports from Philadelphia suggested McInerney wasn't the most popular player and that he'd make his displeasure known when teammates didn't get him the ball.
He'll get a chance to face his former team on April 26 when the Union visit Saputo Stadium.
"It'll definitely be an emotional game for me because I've known a lot of them for five years, but it'll be like every other game — you just go out and play," he said.
"I think it will be fun. Obviously, Philly didn't have me in their plans and I think it's good that we play them in two weeks just to get the game out of the way. And hopefully I can score and win the game and kind of shove it in their face."
The Impact had an eye on McInerney for some time and they knew the Union wanted Wenger, a Pennsylvania native and converted defender who struggled to find himself as a forward in Montreal.
"Both teams got quality players," said Klopas. "Maybe they were looking at Andrew because he can play different positions, while Jack is a striker. It's good that we got another guy with quality around the goal who can score."
Last season in Chicago, Klopas made a similar move when the Fire acquired Magee from Los Angeles in May. Magee scored seven goals in his first seven games with the Fire en route to a 21-goal campaign.
McInerney was hot early last season, with 10 goals in his first 15 games. But he seemed to lose his touch sitting idle for a month after being picked for the U.S. Gold Cup squad and not playing. He had only two goals the rest of the season.
This season, he has one goal and an assist in four games, including a helper in a 1-1 draw with Montreal on March 29.
"I definitely feel I have something to prove," he said. "A lot of people in Philly are disappointed.
"I feel if I come here and show I'm still capable of what I did at the beginning of last year, that will help."
The players charged with feeding Di Vaio and McInerney the ball will be centre midfielder Felipe Martins and right winger Justin Mapp, who once played for Philadelphia.
"He's a young, hungry player, a quiet guy," Mapp said of McInerney. "I know he wants to get here and score goals and prove anyone who doubted him wrong."
Defender Nelson Rivas was back at practice after rehabbing a hamstring injury. It was uncertain if he will be ready to play this week.
Midfielder Hernan Bernardello, who injured an ankle Saturday against New York, missed practice and is also a question mark.