Both contracts were for the 2012 season.
Sonnanstine has spent his entire five-year career with the Tampa Bay Rays and has made 80 starts, but has been used primarily as a reliever for the past two seasons. Overall, the 28-year-old southpaw is 28-31 with a 5.26 earned run average and one save.
In 2011 Sonnanstine made 15 appearances -- four starts -- with the Rays and posted an 0-2 record with a 5.55 ERA.
Corpas missed the entire 2011 campaign while recovering from Tommy John surgery. He made 56 relief appearances in 2010, going 3-5 with a 4.62 ERA and 10 saves.