Zarraga, 25, is a former 44th-round Draft pick who has been bouncing around the Brewers' system since 2008. In 2014, he batted .309 with a .416 on-base percentage in 92 games between Double-A Huntsville and Triple-A Nashville, with a career-best 18 doubles.
Adam McCalvy is a reporter for MLB.com. Read his blog, Brew Beat, and follow him on Twitter at @AdamMcCalvy. This story was not subject to the approval of Major League Baseball or its clubs.