O'Sullivan, 25, went 14-7 with a 4.23 ERA (67 ER/142.2 IP) and 70 strikeouts against 46 walks in 31 games, 19 starts, between Triple-A Omaha and Triple-A Las Vegas in the Kansas City Royals and Toronto Blue Jays organizations last season. The right-hander was acquired by the Blue Jays in June this past season, finishing the season by going 9-3 with a 2.72 ERA (27 ER/89.1 IP) and 44 strikeouts against 23 walks in 14 total starts for Triple-A Las Vegas. A native of San Diego, O'Sullivan graduated from Valhalla High School and attended Grossmont Community College in nearby El Cajon, Calif., before being selected by the Los Angeles Angels of Anaheim in the third-round of the 2005 First-Year Player Draft. He has gone 10-14 with a 6.13 ERA (132 ER/193.2 IP) and 91 strikeouts against 73 walks in 43 games, 34 starts, over parts of three Major League seasons in his career with the Angels (2009-10) and Royals (2010-11).
Ray, 28, spent the 2012 season in the Padres organization, going 2-3 with a 3.71 ERA (22 ER/53.1 IP) and 63 strikeouts against 22 walks in 49 relief outings between Double-A San Antonio and Triple-A Tucson. The right-hander spent the majority of the season with Tucson, going 1-3 with a 3.57 ERA (18 ER/45.1 IP) over 40 outings for the Padres' Triple-A affiliate. Originally selected by the Oakland Athletics in the eighth round of the 2005 First-Year Player Draft, Ray previously signed with the Padres as a minor league free agent in May 2011. Over parts of eight minor league seasons in the Athletics (2005-10) and Padres (2011-12) organizations, he has gone 28-21 with a 3.42 ERA (137 ER/361.0 IP) and 385 strikeouts against 183 walks over 216 outings, 21 starts.
Stange, 26, spent the majority of the 2012 season with San Antonio in the Padres organization, going 3-6 with a 3.35 ERA (20 ER/53.2 IP) and 64 strikeouts against 12 walks over 46 relief outings for the Missions. The right-hander also had two outings with Tucson and three with Triple-A Reno before signing with the Padres as a minor league free agent in May this past season. Originally signed by the Arizona Diamondbacks as a seventh-round selection in the 2006 First-Year Player Draft, Stange has gone 26-24 with a 4.17 ERA (147 ER/317.0 IP) and 311 strikeouts against 127 walks in 256 games, one start, over parts of seven minor league seasons in the Diamondbacks (2006-2012) and Padres (2012) organizations. He also has worked in four Major League games for the Diamondbacks in 2010.
Petit, 28, hit .260 (98-for-377) with 24 doubles, 10 home runs, 45 RBI and 51 runs scored in 111 games played for Triple-A Columbus last season in the Cleveland Indians organization. The Venezuelan native was originally signed by the Oakland Athletics as a minor league free agent in July of 2001. Petit made his Major League debut for the Athletics and hit .278 (15-for-54) in 25 games over parts of two seasons (2008-09) for Oakland. Over parts of 10 minor league seasons with the Athletics (2002-09), Texas Rangers (2010) and Indians (2012), he has hit .266 (906-for-3411) with 163 doubles, 22 triples, 51 home runs, 388 RBI and 464 runs scored in 938 games played.
Rivera, 29, hit .226 (65-for-288) with 14 doubles, one triple, 10 home runs, 34 RBI and 31 runs scored in 95 games for Triple-A Rochester in the Minnesota Twins organization last season. A native of Puerto Rico, the backstop was originally signed by the Seattle Mariners as a second-round selection in the 2001 First-Year Player Draft. Over parts of four Major League seasons with the Mariners (2004-06) and Twins (2011) he has hit .193 (49-for-254) with 10 doubles, four home runs, 15 RBI and 20 runs scored in 98 games played.
Rodriguez, 27, made his Major League debut for the Padres in 2012. The catcher played in two games total for San Diego last season and collected just one hit, a solo home run in his first Major League plate appearance on August 2 against the Cincinnati Reds at Great American Ballpark. Rodriguez also played in 101 games between Single-A Lake Elsinore and Tucson in 2012, spending the majority of the year with Lake Elsinore. The Cuban-native was originally signed by the Reds as a 20th-round selection in the 2006 First-Year Player Draft and has hit .225 (264-for-1173) with 53 doubles, one triple, 38 home runs, 136 RBI and 130 runs scored in 338 games across five minor league seasons in the Reds (2006-08) and Padres (2011-12) organizations as well as two seasons (2009-2010) in the Independent Leagues.