Moseley was enjoying a career-best year in 2011 (3.30 ERA in 20 starts) before missing the last two months of the season after dislocating his left shoulder while swinging a bat. The injury bug followed Moseley to this season, as he was limited to just one start in 2012 after undergoing surgery on his throwing shoulder.
Stauffer posted a 1.87 ERA as a starter and reliever in 2010 and enjoyed a solid full-time return to the rotation in 2011, when he was the Padres' Opening Day starter and posted a 3.73 ERA, a 2.42 K/BB ratio and a 6.2 K/9 in 31 starts. Like Moseley, Stauffer was limited to just one start in 2012 due to injury, in this case elbow problems that required surgery in August. Stauffer tells the Union-Tribune (Twitter link) that he would like to return to San Diego, though it would have to be on a minor league contract.
Both pitchers were entering their third year of arbitration eligibility and both were seen as likely non-tender candidates by MLB.com's Tim Dierkes in his look at the Padres' arb-eligible players. Matt Swartz projected Moseley to earn $2MM in 2013 while Stauffer was on pace to earn $3.2MM.