Carpenter was acquired by the Red Sox from the Chicago Cubs last offseason along with Aaron Kurcz in exchange for Jair Bogaerts. The right-hander went on to appear in eight games for Boston, allowing six runs on seven hits with 10 walks and two strikeouts in six innings.
Carpenter's only other major league appearances came in 2011 as a member of the Cubs. He only allowed three runs over 9 2/3 innings, but he walked seven and allowed 12 hits over that span.
Carpenter spent much of the 2012 season in the Red Sox minor league system. Most of his appearances came at the Triple-A level, where he maintained an ERA of 1.15 with 9.8 strikeouts and 4.6 walks per nine innings over 15 2/3 innings. Combined the 27-year-old posted a 2.08 ERA over 21 appearances, including four starts.