 Prior to the start of the 2015 season, "Baseball America" ranked Reyes as the 51st-best prospect in all professional baseball, and "Baseball Prospectus" ranked him 55th.Jim Callis selected Reyes as the Cardinals' top prospect for 2015, and although he did not make MLB.com's top 100, Callis named him the best pitching prospect not on that list.The recipient of a late growth spurt, it was in class-A level that Reyes began to throw at and had grown to a height of 6'4" (190 cm).