16 months ago, Julio Teheran was poised to begin an elite career as a starting pitcher for the Atlanta Braves. A Top 5 prospect in the majors, the 21-year-old was competing with fellow youngster Randall Delgado for the final spot in the rotation, with most assuming Teheran would easily grab the spot. After a 5-HR start early in the spring and overall ineffectiveness, he found himself repeating AAA after posting a 2.55 ERA and 3.06 FIP the year before in 24 starts.
As surprising as that was, his 2012 AAA regular season performance was dumbfounding. He wound up averaging only 5 innings a start, running a 5.08 ERA. It wasn't too unlucky either, as his 4.83 FIP indicates. There was some talk of the Braves trying to change his motion trying to prevent injury, an interesting move for such a high prospect. The strikeouts dropped further, and he allowed as many homers that year (131 IP) as he did his previous 3 seasons in the minors (368.2 IP). With a handful of iffy starts at the major league level, doubt was starting to creep into the minds of many.
Fortunately, the Braves lost no faith in him, trading away Tommy Hanson and Randall Delgado, leaving Teheran as the only option for the #5 spot. He rewarded the Braves with a dominant spring, only allowing 7 hits and 9 walks in 26 IP, striking out 35. That looked like the uber-prospect expectations, but he has completely changed styles during the regular season.
Teheran has essentially turned into Kyle Lohse: lots of strikes, average amount of K's and grounders. Like Lohse, Teheran found success when adding a sinker, as he is getting 70% grounders on the pitch. He still throws his four-seamer about half the time, getting a lot of misses despite a lack of life, averaging about 91 MPH. Both his slider and curveball are a bit loose, with the slider more effective this year. His once-good changeup is now all-but-gone.
Hitters are swinging a lot against him (49%) because he's pounding the zone (nearly 55%). His walk rate is a bit deceiving, as he is not afraid to pitch inside and has hit six batters already this season, on par with minor league averages. His contact rates in and out of the zone are essentially league-average, a sign of his undeveloped offspeed pitches. His batted ball profile reads almost identical to league-average: 45% GB, 11% IFFB and HR/FB, leading to an average .297 BABIP.
With his ERA half a run below his FIP, we know that batted balls doesn't explain it. He has been very successful with runners on base, allowing a .279 wOBA. He's been even better with RISP, allowing a .245 wOBA, leading to an 82% strand rate. A concerning, and expected given his successful pitches, split is his struggles against lefties. With his sinker and slider working right now, the righty is stifling RHB to the tune of a .263 wOBA, while LHB are 100 points higher. Unless he is able to regain his changeup, I don't see this trend changing in the near future.
There were times people saw some Pedro Martinez in Teheran, so Lohse comparisons may be a disappointment to some, but at 22, he is getting hitters out at an average rate. If he is able to tighten up his breaking balls and rediscover his changeup, Teheran could develop into a solid starter who could challenge for CYAs with a bit of luck. His delivery is still a bit violent and he's not that big (6'2", 175-ish), which creates some injury concerns. His ability to throw strikes is setting a nice floor for his career, but without the ability to strike hitters out, he may not end up being much more than he is right now.