Romero was in the Orioles' system earlier this season, going 1-0 with a 2.51 ERA (14.1IP, 4ER) and 13 strikeouts in 17 appearances for Triple-A Norfolk. He pitched to a 3.12 ERA (8.2IP, 3ER) in eight games with Triple-A Columbus.
He is 34-28 with a 4.15 ERA (657.1IP, 303ER) in 675 games (22 starts) in a 14-year career with Minnesota (1999-2005), the Angels (2006), Boston (2007), Philadelphia (2007-2011), Colorado (2011) and St. Louis (2012). Romero has held left-handed hitters to a .218/.313/.293 line in 1,121 plate appearances over his career.
Rojas batted .226/.285/.248 in 48 games with Double-A Bowie and Triple-A Norfolk this season.