Bullock, a 24-year-old right-hander, was selected by the Twins in the second round of the 2009 Draft and traded to Atlanta in March 2011. He split this past season between Double-A Mississippi and Triple-A Gwinnett, compiling a 6.34 ERA over 59 2/3 innings with 67 strikeouts and 56 walks. He was stronger in the Southern League, where he had a 3.89 ERA in 39 1/3 innings.
In four Minor League seasons, the Florida native has a 4.33 ERA over 218 innings, averaging 11.7 strikeouts per nine innings.
Bullock will begin serving the suspension at the start of the 2013 season.