Of all the minor league relievers signed by the Rays last off-season, one seems to be separating himself from the pack. Winston Abreu has faced 91 batters this season and 41% has been victims to strikeouts. A minor league lifer, Abreu has some 38 innings in the majors versus 822 in the minors. It's hard to say why, in 191 games at the Triple-A level Abreu has a 11.2 K/9, 4.1 BB/9, and 0.5 HR/9. Compare those to Grant Balfour's Triple-A numbers; 129 games, 11.7 K/9, 3.2 BB/9, 0.6 HR/9 and it's hard to see a statistical reason as to why Abreu has been sentenced to a career in purgatory.
Thankfully, we do have some PItchFx data from Abreu's 2007 stint in Washington. Fastball/slider pitcher, his fastball sat 92-94, moving six inches to righties and having good vertical jump. His slider sat ticks lower at 84-86 with decent enough break. Through those 510 pitches in Washington, Abreu had an impressive 13.9% swinging strikes. Somehow Abreu has averaged 20.4% swinging strikes over his last ~1,200 minor league pitches. The ability to miss bats is here. The only problem with Abreu at the major league level has been homeruns, which is a big problem, but it's not something that has popped up in his minors career.
If you want the Rays 2009 version of Balfour, it could be Abreu.