OAKLAND -- The A's added bullpen depth on Wednesday by acquiring right-handed reliever Sandy Rosario from the Red Sox in exchange for a player to be named or cash considerations.
Rosario was with Boston for all of five weeks, after the Red Sox claimed him off waivers from Miami on Oct. 17. The 27-year-old pitched in 10 games with the Marlins over the last three seasons, compiling a 15.26 ERA along the way.
The Dominican Republic native began the 2012 campaign at Triple-A New Orleans, posting a 1.04 ERA in 25 relief appearances and converting all 16 of his save opportunities, before earning a well-deserved promotion in June. He struggled, though, posting an 18.00 ERA in four appearances, before hitting the disabled list with a strained right quadriceps.
Rosario was deemed healthy by the end of August and optioned to Double-A Jacksonville at the time.
To clear a spot on the 40-man roster for him, the A's designated outfielder Jermaine Mitchell for assignment. Mitchell, a fifth-round Draft pick by the A's in 2006, hit .252 with six home runs, 15 doubles, 11 triples and 38 RBIs in 108 games with Triple-A Sacramento in 2012.
Jane Lee is a reporter for MLB.com. Read her blog, Major Lee-ague, and follow her on Twitter @JaneMLB. This story was not subject to the approval of Major League Baseball or its clubs.