The Red Sox acquired Garcia from the Angels on Tuesday for an unspecified return, Jon Heyman of the New York Post reports.
Garcia briefly stepped in as the Halos' closer after the departure of Carlos Estevez but has now been traded himself. The 37-year-old Garcia joined Anaheim on a one-year deal during the offseason and has a 3.71 ERA, 1.17 WHIP and 40:14 over 43.2 innings this year. He should serve as a setup man to closer Kenley Jansen, while Ben Joyce is primed to take over as the Angels' closer.