 Sinkbeil was drafted by the Florida Marlins in the first round of the 2006 Major League Baseball Draft out of Missouri State University.Sinkbeil was named the #77 prospect in baseball by Baseball America before the 2007 season.On July 16, 2007, while pitching for the Jupiter Hammerheads, Sinkbeil was named Florida State League co-pitcher of the week, sharing the award with Phil Coke.