Maxwell agreed to a minor league contract with the Marlins on Monday, Matt Eddy of Baseball America reports.
Maxwell struggled mightily at the plate with the Giants this season, slashing .209/.275/.341 in 100 games, leading to his eventual removal from the team's 40-man roster in September. He has never enjoyed too much success at the major league level outside of slugging 18 homers in 2012, but he could have a chance to make the big league roster out of spring training.