A speedy and versatile infielder, Rosario has played second base, third base and shortstop in his six year career. Although he is new to the Atlantic League, Rosario played for Blue Crabs manager Butch Hobson in 2007 with the Can-Am League Champion Nashua Pride, and was also named league player of the year that season. In 2008 Rosario joined the San Francisco Giants organization and hit .298 with 11 home runs and 51 RBI for Double-A Connecticut. Rosario sports a career .315 average, along with 42 home runs and 223 RBI. He also has 63 steals and 22 triples lifetime. Rosario began his career in the Tampa Bay Rays farm system.