Burns, 24, has gone 1-2 with a 2.63 ERA (19 ER/65.0 IP) and three saves in 53 relief appearances for Triple-A Tucson this year. The right-hander has not allowed a run in his last 15 outings for Tucson (dating back to June 30), recording a scoreless streak of 18.2-innings during which he allowed just five hits while striking out 21. Originally signed as an eighth-round selection by the Cleveland Indians in the 2009 First-Year Player Draft, Burns has gone 7-11 with a 2.20 ERA (52 ER/212.1 IP) and 91 saves in 183 minor league relief appearances over parts of four seasons in the Indians (2009-11) and Padres (2012) organizations. He will make his Major League debut in his first appearance with the Padres.
Wells, 35, made seven starts for the Padres, going 2-4 with a 4.58 ERA (19 ER/37.1 IP). Over parts of 12 Major League seasons with the Chicago White Sox (1999-2001), Pittsburgh Pirates (2002-06), Texas Rangers (2006), St. Louis Cardinals (2007), Colorado Rockies (2008), Kansas City Royals (2008), Washington Nationals (2009), Cincinnati Reds (2009) and Padres (2012), Wells has gone 69-103 with a 4.71 ERA (700 ER/1338.1 IP) in 296 games (219 starts).