Mas himself has not publicly addressed his bid for the Marlins, and he did not respond to several requests for comment for this article. But those who know him describe him as a driven businessman and committed civic leader with, among other things, an abiding interest in sports.

“He loves his Miami and he loves his Cuban heritage,” said Arthur Laffer, the well-known economist from the Reagan administration and a longtime ally of the Mas family.

“Having an in-house owner makes a lot of difference,” Laffer added. “He’ll go to the games. He’ll rain pride on Miami.”

A new owner, especially a local one who understands the diverse cultural landscape of South Florida, could inject new energy into a franchise that has not reached the playoffs since winning the 2003 World Series. The team consistently ranks among the worst in attendance despite a $650 million retractable-dome stadium that debuted in 2012 and was paid for almost entirely by the city and county.

The team’s current owner, Jeffrey Loria, wants to sell the Marlins for an estimated $1.2 billion, nearly eight times what he paid for the club 15 years ago. He is an unpopular owner who has come under fire over the years for failing to invest enough to improve the on-field product.

He is now apparently choosing among three bidders. One group is led by Derek Jeter, the former Yankees great, who has a waterfront home in Tampa, Fla. Tagg Romney, son of Mitt Romney, the 2012 presidential candidate, counts Jeb Bush, the former Florida governor, in his group.

And then there is Mas, who through his personal fortune is believed to be putting more of his own money into the bidding than anyone else in the three groups. Mas sat with Loria during the All-Star Game.