Gamel played his first professional season in 2005 for Milwaukee's Rookie League Helena Brewers. Gamel was promoted to the Single-A West Virginia Power in 2006 and the High Single-A Brevard County Manatees in 2007 in which he posted a 33 game hitting streak bested only by Derek Jeter. He played most of the 2008 season with the Double-A Huntsville Stars before being promoted to the Triple-A Nashville Sounds on August 24. In 2008, he was selected to play in the All-Star Futures Game.