Polanco can earn an additional $125,000 if he appears in 100 games, and another $125,000 if he appears in 120 games.
The Marlins have been looking for an everyday third baseman since trading Hanley Ramirez to the Dodgers in July. According to teams that have spoken with them, the Marlins unsuccessfully explored trades for three young third basemen -- Mike Olt of the Rangers, Nick Castellanos of the Tigers and Jedd Gyorko of the Padres. They also had interest in free agents Brandon Inge and Miguel Tejada.
The deal solidifies the Marlins' lineup following a payroll purge. Other projected starters include Logan Morrison at first, Donovan Solano at second, Adeiny Hechavarria at shortstop, Jeff Brantly at catcher, Giancarlo Stanton in right, Justin Ruggiano in center and Juan Pierre in left.
Hanley Ramirez played 90 games at third this year for Miami before being traded in July. That was part of the salary purge by the Marlins, who pared $146.5 million in future payroll when they swung a trade last month that sent former NL batting champion Jose Reyes, former NL ERA leader Josh Johnson and left-hander Mark Buehrle to Toronto.
The Marlins have a projected 2013 payroll of about $45.75 million. Their payroll on opening day this year was $112 million, not including money received in the Carlos Zambrano trade, but the team finished last in the NL East and drew smaller crowds than expected in its new ballpark.
Polanco, 37, missed 72 games last season with the Philadelphia Phillies because of back, knee, ankle and wrist injuries. He hit .294 in the first two months, but batted just .198, with five extra-base hits, in 130 plate appearances after June 4. He started only two games after July 22 because of lower-back inflammation.
In 2011, however, Polanco started at third base for the National League in the All-Star Game and won a Gold Glove. He has a .299 lifetime batting average and is a Gold Glove winner at both second and third base.
Information from The Associated Press was used in this report.