Left-handed reliever Craig Breslow was acquired by the Red Sox, who sent outfielder Scott Podsednik and pitcher Matt Albers to the Diamondbacks.
Breslow, who signed a one-year deal worth around $1.8 million over the offseason, has a 2.70 ERA in 43 1/3 innings this year. He spent 2011 with Oakland, and the 31-year-old pitched for the Red Sox in 2006.
Podsednik, 36, has missed time with a groin injury, but is hitting .387 in 70 plate appearances.
Albers has a 2.29 ERA in 39 1.3 innings pitched in 2012. One of the keys being he is arbitration eligible through 2013, with a $1.08 million salary this season.