The deal is believed to be for one year and $2.75 million plus performance incentives, per the Miami Herald, a bit less than the $5 million the club had saved by dealing Yunel Escobar to the Tampa Bay Rays.
The Marlins' search for a replacement at the hot corner was fraught with disappointment, as the club showed interest in players like Jack Hannahan and Mark Reynolds only to watch them sign elsewhere, dissipating an already thin free-agent market at the position.
Miami got so desperate to find an answer at third that the club reportedly scouted veteran Miguel Tejada -- who was released from the Orioles' Triple-A affiliate in May -- in the Dominican winter league this past week.
Polanco, 37, spent the past three seasons with the Philadelphia Phillies. He put up serviceable numbers in his first two years with the club -- earning an All-Star bid in 2011 -- but struggled his way through 2012 because of injuries. The veteran infielder appeared in just 90 games this past season, hitting .257/.302/.327 with two home runs.
Polanco is now a 15-year big-league veteran and is a career .299/.344/.403 hitter.