They weren't necessarily cheering for the home team.
Organizers say about 1,000 Expos fans, hoping to attract the attention of major league baseball's movers and shakers, packed into the outfield bleachers at the Rogers Centre on Saturday afternoon.
The group wore the defunct club's traditional red, white and baby blue and held up signs promoting their cause.
"Our goal is to celebrate the history of the Expos and show that there is still a viable market for it," said Matthew Ross, who runs the website Expos Nation and helped organize the trip.
"We do everything we can to drum up nostalgia for the team and at the same time focus on the future."
About 200 people made a similar trek to Toronto last season.
This year, the group convinced a former player, Bill Atkinson, and manager, Jim Fanning, to attend.
Nearly a decade after the Expos left town, there's a small but growing movement to bring a team back to the city.
The possibility has become a recurring topic on local talk radio shows and has even influenced Montreal street fashion.
The team's logo has become a source of city pride and a statement for young people barely old enough to have seen them play.
Ross said the pain of the Expos messy 2004 departure has begun to dissipate.
These days, people are more focused on joyful memories, and Expos greats like Andre Dawson, who was inducted into the Hall of Fame in 2010, he said.
The Montreal Baseball Project, a group founded a year-and-a-half ago by former Expo Warren Cromartie, is a focal point of the renewed interest in the team.
At events around the city over the past year, Cromartie has made his sales pitch for bringing back baseball.
"The slogan that I put out there, that I want to continue to put out there, is: 'Montreal wants baseball back,'" Cromartie said in an interview.
Cromartie pointed to the death of Hall of Fame catcher Gary Carter, a fan favourite when he played at Montreal's Olympic Stadium, as a key rallying point.
Last summer, several former Expos returned to Montreal to pay tribute to Carter and meet with fans. A Montreal street was named after him earlier this year.
Cromartie said the revival of the Canadian dollar, more television revenue, the advent of social media and increased revenue sharing in baseball make a team in Montreal a realistic possibility.
His group has about $400,000 from the Montreal Board of Trade and private business partners to explore the possibility of bringing a team back.
A feasibility study in the works could be ready by September, he said.
Even if it doesn't happen anytime soon, Ross believes the city is a viable baseball market under the right circumstances.
It's no accident the group chose to attend a game featuring the Tampa Bay Rays, one of the league's more troubled franchises, he said.
In the past few years the team has been rumoured to be on the move and the team's owner recently mused that Montreal was a good baseball market.
When asked whether he believed the Expos would ever return, Ross, 35, said it would be "very difficult and very tough."
"That doesn’t mean that we can’t stir the pot a little bit," he said.
That strategy appeared to work on Saturday.
The event created plenty of buzz on social media, even drawing the attention of political leaders.
Liberal leader Justin Trudeau, a Montreal MP who attended Expos games with his prime minister father as a child, sent out a series of messages supporting the cause.
"Good to see more than 1,000 members of Expos Nation attending the Blue Jays game today," Trudeau wrote on Twitter. "Gone but not forgotten!"
Prime Minister Stephen Harper later got in on the act as well, saying on Twitter, "I hope that the efforts of Expos Nation will one day be rewarded with a team in Montreal."