What to Make of Julio Teheran

In the FanGraphs Experts ottoneu League, I nearly traded Julio Teheran this off-season. I shopped him hard, targeting OF help. But holding him on a cheap contract was just too attractive – he’s 24 years old and coming off two straight excellent fantasy seasons.

But 2015 is not off to a good start. I was smart enough to bench him on Tuesday night, but after allowing 7 R (3 ER) over 5.1, his numbers on the year are not pretty. 27 IP, only 22 K, 12 BB, 6 HR. His 4.67 ERA is bad; his 6.07 FIP is worse. So what gives?

Well part of it certainly a HR/9 of 2.00, driven by an unsustainably high 21.4% HR/FB rate. Last year, only six batters had a HR/FB rate over 20%. Basically, Teheran is making literally everyone look like they have Chris Carter’s power. That is…uh…not good.

Part of it is that BB rate. His zone percentage – previously hovering between 51% and 53% is now under 49%. His first strike percentage, previously around 60%, is at a career low 50.4%. After years of very good BB% (under 6%) he is up to 9.9%. Last year, a grand total of five SP posted a BB% that high. Mostly because anyone who does allow walks that often is destined to lose their job.

Or to be injured. Loss of control and loss of velocity are two leading indicators of arm injuries (sometimes serious ones). Teheran has one half of that – what about the other?

Based on Pitchf/x data, his four-seamer is down from 91.3 mph last year to 91.1 this year. It was at 92.1 in 2013. His two-seamer is actually up from 88.5 to 89.3. He is also using this pitch more often this year (and his four-seamer less often) than in the past. His slider, curve and change? All also slower than in the past.

There is another smoking gun here – his O-Swing% (the percent of pitches outside the zone that batters chase). Previously over 30%, it has dropped to 25.3% this year. As a result, his swinging strike rate has plummeted too. The problem is exacerbated because he just plain cannot control his off-speed pitches. His curve and change have been in the zone 45% and 40% of the time for his career; they are down to 34.0% and 24.1% this year.

I see two possibilities here. One explanation is that he is injured. He isn’t controlling his pitches, he is losing his velocity, and the next step is word of an arm injury. That’s a possibility, but I see no reports of pain, discomfort or anything else. If he is hurt, it is not public knowledge. And I talked to Jeff Zimmerman, our resident expert on potentially injured pitchers, and he is not ready to put Teheran on his warning list. He had a big drop in velocity in his previous start (before last night), but it bounced back. If the velocity stays down 2-3 straight games, he’ll be concerned.

The other is that his inability to get ahead of batters is allowing them to sit on pitches, and get a better read. They can sit dead red, ignore the off-speed stuff (since he can’t get strikes with it anyway). And when “dead red” means a 90 mph fastball, big league hitters are going to tee off in a big way – like 2 HR/9 IP big.

In either case, Julio Teheran is basically unusable right now. Until he is able to get those off-speed pitches into the strike zone, he’s going to continue to walk everyone and the guys he doesn’t walk will continue to hit the ball really, really hard. Until you see the walks come down (and more specifically, the off-speed pitches hitting the zone) I’d keep him riding the pine.

I might even look to sell low.

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Chad Young is a product manager at Amazon by day and a baseball writer (RotoGraphs, Let's Go Tribe), sports fan and digital enthusiast at all times. Follow him on Twitter @chadyoung.

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About 3 starts ago he seemed to tweak a knee on a shot back through the mound. He has struggled since.