Closer of the future - Craig Hansen
The Red Sox needed a closer for the future and drafted Craig Hansen in the first round of the 2006 draft. Hansen was 6'6" and had a killer heater and a hard-breaking slider.
I saw Hansen in the Cape Cod League, and it was pure, OMG, how can you hit this guy? That CCL season, Hansen did not allow an earned run that season, and after his junior year at St. John's, he was signed to a massive contract by Boston.
Hansen's Boston career was disappointing, and that is an absolute understatement. Hansen appeared on the right track at Pawtucket in 2008, and the few times I saw him, it appeared he had put it together, but that was an illusion. Hansen was soon shipped to Pittsburgh, and the change in scenery did nothing.
What happened? Hansen was diagnosed with brachial plexus neuropathy that caused nerve numbness, and that explained why his BB/9 was in the ionosphere and that heater was suddenly listless.
For the Red Sox, all was not lost since Jonathan Papelbon emerged to solidify the closer role for several seasons. For Hansen, his career disappeared primarily via injury, but what could have been was 300+ career saves.