One of the hallmarks of the Rays' front office has been the ability to build an effective bullpen on the cheap. But in contrast to the rest of the team, the relief corps hasn't been homegrown. Instead of cost-controlled pre-arbitration players, they've bargain hunted the free agent and trade markets. Since the start of the 2008 season, the only pitchers who tallied at least 20 relief innings and were originally drafted or signed by the team are Jason Hammel and Andy Sonnanstine. Granted, this doesn't tell the whole story since the Rays could fairly be credited with developing J.P. Howell as a reliever, but even including him there's not exactly a long track record of homegrown relievers. Here are a few pitchers in the system who could break that trend:
Marquis Fleming, RHP, Montgomery Biscuits - It's been something of a yearly tradition for the organization to have a reliever toy with Florida State League hitting. Ryan Reid did it in 2008, Matt Gorgen in 2009, and last year, well, a host of guys did it: Neil Schenk, Zach Quate, and Fleming to name three. Like Reid and Gorgen before them, Schenk and Quate have seen their strikeout rate plummet in double-A. Fleming? His K% improved from an already-impressive 33.1% to 36.4%.He gets it done mainly on the strength of a plus (maybe plus-plus) change-up. His fastball is average or perhaps a tick above, but he gets excellent velocity differential on the change-up with similar arm action and it's effective against both lefties and righties. A 24th-round pick out of Cal State-Stanislaus in 2008, we're probably not looking at a closer or set-up man because of some sometimes-shaky control (he's walking a career-high 4.5 hitters per 9 innings this season). There's not much precedent in the Rays system given how many pitchers have hit the wall at double-A, but the one comparable pitcher I thought of was David Robertson with the Yankees. He was also a late-round college pick, and in his age-23 season in the minors, he struck out 12.9 and walked 3.9 per 9 innings (Fleming's current rates: 13.0/4.5). Robertson has been far from a control artist in the majors with a walk rate a hair under 5.0 per 9, but he's found success including a 1.15 ERA and 14.0 K/9 this season. Robertson thrives thanks in large part to one plus-plus pitch, though his is a curveball.
One other note on Fleming: I like how the Rays seem to be developing him as a multi-inning reliever. In 126 appearances (including one start), he's thrown 222 innings, so he's averaging over five outs per appearance. In an age where starters are pitching fewer and fewer innings (James Shields excepted), I think some team is going to find an edge and get a reliever or two to give them 80 or 90 quality innings.
Matt Bush, RHP, Montgomery Biscuits - If power-armed relievers are more your thing, Bush is your man. Okay, so technically he wouldn't count as homegrown since the Padres both drafted him and converted him to a pitcher, but 85% of his innings have come in the Rays system. By all accounts his personal problems are behind him. Despite his small stature (5-9/180) he might throw harder than anyone in the system, capable of firing in the upper-90s. He throws a curveball that grades out as at least average.
His 14.0 K/9 beats out Marquis Fleming for the team lead. His 4.9 BB/9 is below-average, but after issuing seven walks in 8.1 innings in April he's walked eight in 19.1, a more respectable 3.7 per 9. His biggest problem has been his 10.7 hits per 9 innings. I'm sure spotty command has played into that, but a .455 BABIP is almost comical. That will assuredly come down, and as a result so will his strikeout rate (since more balls in play will be turned into outs, he'll face fewer hitters), though it'll still be well above-average. As long as he stays healthy and his control doesn't implode, he should avoid becoming the first #1 overall pick since Brien Taylor to fail to make the majors.
C.J. Riefenhauser, LHP, Bowling Green Hot Rods - A list of future relief candidates could really include every starter in the system (particularly Alex Torres and Chris Archer), but Rulenfurter caught my eye because of how dominant he's been against left-handed hitters this season. They're hitting just .118 against him and have struck out 48 times against six walks. Righties have hit .278 with a 28-13 K-BB rate. The Rays will continue to develop him as a starter for now, but without overpowering stuff or an out pitch against righties, there's a good chance he winds up as a lefty specialist. Runamaker was a 20th-round draft pick from Chipola Junior College in 2010, which I bring up only to mention that Jose Bautista was a 20th-rounder from Chipola 10 years earlier. Rowengarter's fastball tops out at only 91 mph or so, but has enough deception and pitchability to maintain success against lefties at a higher level. If it all breaks right, one day he might just be Rookie of the Year.