Williams, 23, was signed out of the independent Frontier League in May 2011. He was 0-2 with a 3.00 ERA in three starts and 10 relief appearances at Huntsville.
Adam McCalvy is a reporter for MLB.com. Read his blog, Brew Beat, and follow him on Twitter at @AdamMcCalvy. Kevin Massoth is an associate reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.