Pearce, 28, was hitting .254 with four doubles, three home runs and 14 RBIs in 28 games for Baltimore this season. He was designated for assignment last Sunday. The right-handed hitting corner infielder and outfielder began the regular season with Triple-A Scranton/Wilkes-Barre in the Yankees organization, where he hit .318 with 11 home runs and 30 RBIs in 53 games, before being traded to Baltimore on June 2.
Pearce has spent parts of each of the last six seasons in the Majors with Pittsburgh (2007-11) and Baltimore (2012) and has played in 213 Major League games.
Galarraga, 30, owns a 3-2 record and a 3.97 ERA in 10 starts in the Astros Minor League system this season -- nine with Oklahoma City, one with Class A Lexington. The veteran right-hander was signed by Houston as a Minor League free agent on May 21.
Galarraga began his year in the Baltimore organization before being released following Spring Training. Galarraga owns a 26-30 Major League record with a 4.69 ERA in 95 games (86 starts) across parts of five seasons with Texas (2007), Detroit (2008-10) and Arizona (2011).
Abad, 26, has posted a 3.86 ERA in 30 appearances for the Astros this season. This is his second option to Oklahoma City in 2012, where he owns a 1-0 record with two saves and a 0.00 ERA in seven appearances. Abad owns a career record of 1-5 with a 4.65 ERA in 81 appearances over the last three seasons with Houston.
Del Rosario, 26, was optioned to Oklahoma City on Friday before being outrighted on Saturday. He owns a 7.80 ERA in 15 relief appearances for the Astros this season. Other than a month-long DL stint, Del Rosario spent the entire 2011 campaign on Houston's roster, posting a 4.58 ERA in 54 relief appearances. He has a career 1-4 record with a 5.19 ERA in 80 Major League appearances with Cincinnati (2010) and Houston (2010-12).
Rodriguez, 24, has spent the majority of this season with Oklahoma City, where he has gone 3-7 with a 6.67 ERA in 23 games (13 starts). He made one start for the Astros on May 8 vs. Miami, tossing six innings, allowing two runs on two hits. The Astros 2010 Rule 5 Draft pick spent all of the 2011 season with the Astros, posting a 1-6 record and a 5.27 ERA in 43 appearances, including eight starts.
With the moves, the Astros 40-man roster remains full.