[Editor’s Note: Since this post was written, Mejia left his most recent start with elbow discomfort, likely from bone chips in his elbow. He may have thrown his last pitch of the 2013 season, but by all accounts should be healthy coming into 2014. His future value remains unchanged.]

Starting pitching upside is among the rarest of fantasy baseball jewels, and the deeper your league the greater the premium on finding it. This time of year it can pay big dividends for a rebuilding owner to cast his or her eyes to the margins and do a little “Where are they now?” review of the post-hype and convalescing sleepers of days past. You’ll often be able to find some cost-controlled nuggets heading into the off-season, and using your remaining FAAB budget or waiver claims to this end can be an extremely cost-effective way to add future value to your team.

Enter Jenrry Mejia. Mejia’s post-hype status is the result of dual threats arm health and Omar Minaya. Mejia entered 2010 as a 20 year-old knocking on the doorstep of BA’s Top 50 (#56), and he performed quite well out of the gate at AA with a stellar 1.32 ERA (2.83 FIP) over 6 starts. A walk rate over 4.5 confirmed his youth and raw command but he was subsequently fast-tracked to the Major League bullpen after a AAA pit stop. While his component ratios were weak over 33 appearances he managed to hold his own pretty well for a 20 year-old in the Show. His season ended prematurely due to a shoulder strain though, and he succumbed to Tommy John surgery the following spring. The Alderson regime has been extremely cautious in his rehab program and they shelved him quickly this spring at the first twinge of a tender elbow. But since his return to the mound in July he’s been lights out, and therein lies his intrigue.

Small sample size caveats are warranted here as Mejia’s thrown all of 27 1/3 innings over five starts at the big league level. But there are some interesting developments in his pitch selection and execution to date that catch the eye. Most notably he’s developed a slider and it’s been a good one. After years of pairing an electric fastball and solid change with an inconsistent, slurvy deuce he’s tightened his slider significantly this season. The pitch boasts a 2.6 runs-above-average mark, and coupled with a significant boost in usage (21.4%) it goes a long way towards accounting for an O-Swing % that has jumped nearly double-digits on his career average to 38%. A stellar 60.7% first-pitch strike rate has maximized his opportunities to deploy the burgeoning weapon as well.

He’s also managed to maintain his calling-card ground ball tendencies, boasting a GO/AO ratio near 3 thus far. And he’s done it despite a fastball velocity that has dipped significantly from the heady, pre-Tommy John days when scouting reports had him in the mid-90’s. Mejia has claimed this to be an intentional development meant to prevent injury, but it should be noted in big bold red letters that it doesn’t appear to have worked. He’s due to have bone spurs removed from his elbow after the season, and he was pulled from his most recent start in San Diego after just three innings as a result of the injury.

He’s certainly not someone who’s likely to ride in on a white stallion and throw down 200 Cy Young-caliber innings for you next year, nor is he more than a match-ups play for the remainder of this season assuming he’s even healthy enough for that. Ongoing health issues and general inexperience all but guarantee he’ll face strict pitch and innings caps for the foreseeable future. But given his former prospect status, age (he’s still just 23), and flashes of #3 starter potential he’s absolutely someone who – health permitting – warrants a close watch over the next few weeks. And given his current ownership rate of just 13.2% on ESPN he’s an easy flyer to take.