Arizona pitcher Curt Schilling has accepted a trade to Boston after agreeing a three-year contract.
Schilling knows what it takes to win a World Series
Schilling had to waive the no-trade clause in his current contract for it to go through.
The right-hander has partnered Randy Johnson for 3½ years and the pair were co-MVPs in the Diamondbacks' victory over the New York Yankees in the 2001 World Series.
Schilling will try now to lead the Red Sox to a title alongside Pedro Martinez in what could be baseball's most formidable rotation.
"From one Hall of Famer to a potential Hall of Famer," Schilling said of the swap.
Boston will send lefty Casey Fossum and right-hander Brandon Lyon to the Diamondbacks, along with two minor leaguers.
Oakland have acquired Mark Kotsay from San Diego in return for All-Star catcher Ramon Hernandez and outfielder Terrence Long.
The As have taken a calculated gamble on the centre fielder who had a herniated disc in his lower back that hampered him last season.
Kotsay has struggled with injuries during his six major league seasons with Florida and San Diego.
But he has been a consistent hitter with a high on-base percentage