Lee went 9-8 with a 3.71 ERA in 25 appearances (20 starts) with Mississippi this past season. The 27-year-old right-hander spent five seasons in the Red Sox's organization before being released during the 2012 campaign. The Braves signed him later that same year after he spent some time with Rockford of the independent Frontier League.
Sims has gone 4-23 with a 5.12 ERA in the 92 appearances (24 starts) he has made since beginning his professional career with the Braves in 2010. While producing a 8.44 ERA in the 20 appearances (eight starts) he combined to make below the Double-A level this year, the 24-year-old left-hander was attempting to transform himself into a knuckleball pitcher.
Mark Bowman is a reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.