The Expos joined the National League for the 1969 season and remained in the big leagues through 2004 before moving to Washington and becoming the Nationals.
While the Expos failed to draw one million spectators to Olympic Stadium in any of their final seven seasons, a total of 96,350 fans attended a pair of exhibition games there in March between the New York Mets and Toronto Blue Jays.
"I think they would be an excellent candidate in the future. No question about it. That was very impressive," Selig said Tuesday during a question-and-answer session with the Baseball Writers' Association of America.
"They have much work to be done," he said. "There's certainly in my case no hard or angry feeling toward Montreal. We tried to keep a team there. It's a long story now. But I thought that was marvelous."
The Expos once fielded competitive teams and were able to draw over two million fans a season to Olympic Stadium in the late 1970s and early '80s.
They reached their competitive peak in 1994, when a team featuring Larry Walker, Marquis Grissom, Pedro Martinez and John Wetteland had the Expos at 70-44, the best record in baseball, only to see the season and playoffs cancelled by a player strike.
Then came the fire sale of top players and a series of disinterested owners, and the attendence steadily dwindled. The Expos averaged less than 10,000 fans in their last season in 2004, split between Montreal and Hiram Bithorn Stadium in San Juan, Puerto Rico.
Montreal once again being mentioned as the site of a major league team is a relatively recent development, but the successful pre-season series, which included a tribute to the '94 Expos, and the emergence of the Montreal Baseball Project led by former Expo Warren Cromartie appears to have put the city back on baseball's radar.
— With files from The Canadian Press.