The Padres signed three Minor League free agents on Thursday -- right-handed pitcher Sean O'Sullivan, infielder Gregorio Petit and catcher Rene Rivera.All three players will be invited to big league camp in February. O'Sullivan, 25, is a San Diego native who attended Valhalla High in nearby El Cajon. He was drafted by the Angels in the third round of the 2005 Draft. O'Sullivan made his Major League debut in 2009 with the Angels and has played in parts of three Major League seasons (2009-11). O'Sullivan split last season between two Triple-A teams in the Blue Jays and Royals organization. He went a combined 14-7 with a 4.23 ERA in the hitter-friendly Pacific Coast League. O'Sullivan offers the Padres versatility, as he can start or pitch in relief. He throws a good changeup and has good command with a low walk rate. With pitcher Andrew Cashner to miss Opening Day after having surgery last week to repair a lacerated tendon in his right thumb, O'Sullivan could forge his way onto the roster with a strong performance in Spring Training. Rivera has spent parts of four seasons in the big leagues (2004-06, 2011) with the Mariners and Twins. The 29-year-old Rivera gives the Padres some catching depth. He spent all of the 2012 season with the Twins' Triple-A affiliate in Rochester, hitting .226 with 10 home runs and 26 RBIs. The 28-year-old Petit originally signed with San Diego as a Minor League free agent in December of 2010 but he suffered a knee injury playing winter ball shortly thereafter. He likely would have made the roster as an extra infielder in 2011 had he not been hurt. Instead, the team traded for Alberto Gonzalez during Spring Training. Petit is regarded as a good defender who can play in the middle of the infield but is best at shortstop. He appeared in 25 games with the A's in 2008-09. Petit hit .260 with 10 home runs and 45 RBIs last season with Columbus, the Triple-A affiliate for the Indians. Pitchers and catchers report to the team's Spring Training facility in Peoria on Feb. 12. Position players report on Feb. 15 with the first full-squad workout set for the following day.