The Red Sox are adding some depth to their bullpen.
With J.D. Drew set to return to the outfield soon, the Sox optioned outfielder Josh Reddick back to Triple-A Pawtucket and have called up lefty Fabio Castro.
Castro, who signed as a free agent in December, has had stops with the Rangers and Phillies where he recorded a 3.30 ERA.
At Pawtucket, he has a 6.65 ERA in 43.1 innings pitched. In his last eight appearances, he has done better, posting a 3.46 ERA.
Reddick, who has been up with Boston since June 22, went 1-for-8 in his third stint with the Sox. Over his three stints with the big club, he is batting .160.