The goal is to have Toronto FC take part in the Guinness International Champions Cup next summer at a newly expanded BMO Field.
The eight-team, 12-city pre-season tournament this year also features heavyweights Inter Milan, Liverpool, Manchester City, Manchester United, Real Madrid and AS Roma.
Real Madrid defeated Chelsea 3-1 before 67,273 at Miami's Sun Life Stadium to win the 2013 Guinness tournament.
The Milan-Olympiacos game was originally scheduled for New York's Citi Field. Charlie Stillitano, CEO of tournament organizer Relevent Sports, did not offer one specific reason for the move but said he initially thought the Toronto stadium would be unavailable because of the FIFA U-20 Women's World Cup.
He also said New York was hosting other games and the switch gave his company a chance to partner with MLSE and take advantage of an expanded BMO Field.
MLSE president and CEO Tim Leiweke see the pre-season tournament as another step down the road to making Toronto the soccer capital of North America.
An expanded hosting role in the event also give him more ammunition in his bid to secure $20 million more in government funding for the stadium renovation.
The first part of the stadium renovation is slated to start in September and finish in May, with a goal of expanding BMO Field to a capacity of 30,000 in time for the rugby sevens competition at the Pan American Games.
Phase 2 will start after the Games, with a completion date of May 2016. That would mostly involve the roof.
MLSE has committed $90 million to the $120-million plan, with three levels of government kicking in $10 million apiece.
The stadium is owned by the city but operated by MLSE.
Toronto city council has voted in favour of its $10-million contribution. MLSE says the city's contribution will be repaid over 20 years with interest.
MLSE still has to convince the provincial and federal governments.
"We're making progress with the province, in particular," said Leiweke. "They've been very supportive from Day 1. What they're most interested in is this sort of event. They understand that if we can host this tournament next year, it's a huge economic impact for Toronto and the province."
"Our issue has never been the province," he added. "We believe they will be supportive and play their role in the renovation of this stadium. We still have work to do with the feds."
The lack of government commitment has prompted MLSE to put plans to make the field accommodate CFL football on hold. That leaves the Argonauts in limbo as they search for a new home. The CFL team has to be out of the Rogers Centre by the end of the 2017 season.
Asked whether the Argos are out of luck with regards BMO Field, Leiweke replied: "They're not dead in the water, they're just in the fish tank on hold."
The July international friendly makes for a busy soccer week at BMO Field.
There is an Italy-Portugal legends game on July 21. Toronto FC hosts England's Tottenham in a friendly on July 23 before entertaining MLS champion Sporting Kansas City on July 26 in league play.
Leiweke called it "an extraordinary week" for soccer in Toronto and Canada.
With Italy failing to survive the first round at the World Cup, AC Milan should be bringing all its stars to Toronto, according to Leiweke and Stillitano. Olympiacos' roster may depend on how far Greece goes in the knockout stage with eight club players on the national team.
Organizers say tickets for the Milan-Olympiacos game will start as low as $40. But they also offer VIP packages for each team, allowing supporters to take in all of their games.
The 11-day AC Milan package, for example, costs US$7,500 but does include transportation, tickets and hotel. That price was for when New York was hosting the game, however.
The tournament carries a US$1-million first prize. Stillitano said participating teams also get a guarantee. MLSE is paying a fee to get the July 24 game.
The competition makes its money mostly from TV revenue. Organizers say the event will be show in more than 150 countries, with Fox Sports 2 airing it in the U.S.
Being part of the 2015 tournament will mean soccer competition for the Pan American Games. The 2015 FIFA Women's World Cup elected not to stage games in Toronto, choosing instead to play in Vancouver, Edmonton, Winnipeg, Ottawa, Montreal and Moncton.
Leiweke said FIFA and Games organizers had signed off on the tournament coming to Toronto.
Stillitano said he and MLSE were "still putting pen to paper" but said the deal will likely be for more than two years.