The person spoke Friday on condition of anonymity because the deal had not yet been announced. The agreement,.which is subject to a physical, is the first free-agent deal for the Marlins since they began courtships last month with several top players. The deal was first reported by ESPN.
Bell had more than 40 saves each of the past three seasons for the San Diego Padres. This year he had 43 in 48 chances with a 2.44 ERA.
The Marlins are uncertain of the availability of their closer this year, Leo Nunez. He's on the restricted list after he admitted to playing under an assumed name.
Nunez, whose real name is Juan Oviedo, had 36 saves in 42 chances this year with a 4.06 ERA.
The Marlins' move into a new ballpark next year has improved their financial outlook, allowing them to become more active in free agency. They've courted slugger Albert Pujols, shortstop Jose Reyes and left-handers Mark Buehrle and C.J. Wilson, and they're interested in Cuban defector Yoenis Cespedes.
Pujols remains a long shot, but the Marlins have high hopes of signing at least a couple of the others as they prepare to move into a new ballpark.
The burly Bell was an All-Star for the third consecutive season this year, and made his appearance in the game memorable by sliding onto the infield grass before he took the ball to pitch. He'll be reunited in Miami with former Padres relievers Ryan Webb and Edward Mujica, who joined the Marlins a year ago.