Decker is from Hickory Creek, Texas, and went to Lake Dallas High School. After High School, the left-handed pitcher played two years of baseball at Northern Oklahoma College - Enid, and one season at New Mexico Junior College before transferring to the University of Incarnate Word for the 2014 and 2015 seasons. 

At UIW, Decker made 44 appearances as a reliever for a total of 48.2 innings, while holding a 6.29 ERA. After graduating, Decker began coaching baseball, working with the Texas Stix, DFW Post Grad, and Top Prospects Academy.