I make it a point to people relatively more informed about the Rays than myself, and when then conversation turns to minor league relievers, one name that consistently comes up is Brad Schreiber.
Previously drafted in the 42nd round in 2009, and the 40th round in 2012, Brad Schreiber spurned both opportunities to join a major league team and went to college instead. He went undrafted in 2013. The Rays signed him as a free agent out of Purdue, and in the span of two seasons he has blossomed into a highly-rated closer in the minor league system.