The Miami Marlins have a 13-year, $325 million deal in place with Giancarlo Stanton, according to sources.
The deal could keep Stanton under contract through his age 38 season.
Stanton, 25, will receive a crucial early opt-out clause in addition to a no-trade provision, according to sources.
The deal is the largest in North American sports history, eclipsing Alex Rodriguez's $275 million contract with the New York Yankees.