The move is considered a salary dump by the Rangers, as Millwood is owed $12 million in 2010.
Millwood looked rejuvenated last season, posting his best ERA (3.67) since 2005 and going 13-10. After missing the entire 2008 season following Tommy John surgery, Ray struggled throughout the '09 campaign. In 46 relief appearances for Baltimore, the right-hander had a 7.27 ERA, giving up 35 earned runs in 43 1/3 innings pitched.
The deal was first reported by cbssports.com.