Maybe that's one of the downfalls of making two deals with a team over a matter of days: a club can get to know a lot about your assets.
Rodriguez was designated for assignment last week when the White Sox made the signing of left-handed reliever Scott Downs official. To keep Rodriguez the White Sox first had to slip him through waivers, but were unsuccessful.
Rodriguez pitched as high as Triple-A Charlotte in each of the past two seasons. He made 18 relief appearances with the Knights last season, posting a 7.30 ERA after posting a 2.35 mark in 15 appearances at Double-A Birmingham.
The 26-year-old Santos was signed as a free agent out of the Dominican Republic by the Atlanta Braves in 2006 and was acquired by the White Sox in 2008, arriving with Tyler Flowers and Brent Lillibridge. The trade cost the White Sox both Javier Vazquez and Boone Logan.