When the Oakland A's acquired reliever Liam Hendriks from the Blue Jays last winter, they hoped they were getting a strong up-and-coming reliever. His 2015 numbers (2.92 ERA, nearly 10 K/9) might even have put visions of a set-up man in your head, and this FanPost by Dan Bernstein details how Hendriks got to that point after failing as a starting pitcher. Instead of building on that breakout, though, the Aussie began the year as an absolute gascan, posting an 8.27 ERA and an average of nearly two hits per inning.
To add injury to insult, the 27-year-old then went on the disabled list in early May with a triceps strain that later extended to elbow soreness. After about a month, the Liam Hendriks Experiment was going about as poorly as it possibly could have.
But then something happened. Hendriks returned from the DL on June 19, and here's what he's done since:
Hendriks, pre-DL: 11 games, 8.27 ERA, 16⅓ ip, 19 Ks, 1 BB, 28 hits, 2 HR
Hendriks, post-DL: 13 games, 1.62 ERA, 16⅔ ip, 10 Ks, 5 BB, 14 hits, 2 HR
Where to begin? It's easy to point to health as a big factor in Hendriks' struggles -- perhaps he just wasn't quite right in April, and now he's healthy and back to his good self. You could add to the narrative by pointing out that last year he quite famously took on a new role and upped his velocity and did a bunch of things he's not used to doing, which can lead to injury whether you're a pitcher or just a regular person going running for the first time in years. Maybe the novel stresses from 2015 just took a bit longer than one offseason to recover from, and now he's bringing it like he did in Toronto.
That's all speculation, though. It could very well be the truth, but we'll never know to what extent his April may have been hampered by pain. And frankly, I'm not satisfied by a simple, "Dude was hurt, prolly." I want a more complete answer.
We don't know how badly Hendriks was hurt nor for how long, and it almost doesn't matter given that he appears healthy now, but we can at least look and see what he did with his pitches during that time. He passes the velocity test, as his fastball is still averaging around 95 mph on Brooks Baseball, within a half-tick of last year's mark. But how about his pitch selection? Here's his month-by-month usage, including 2015 as a baseline for what he looked like when he was great (via Brooks Baseball):
In 2015, he did his best work from June-August. Those were his hottest months, when he really caught fire. They were also the months when his slider was his main secondary pitch, favored over his sinker. His hard new fastball was still his bread-and-butter, but the slider was the thing that seemed to round him out into a quality pitcher. There's probably not enough there to conclude a true causative effect, but it makes his pitch selection something to keep an eye on.
Rather than do what worked for him last year, though, Hendriks completely changed his game plan in 2016. He went from a well-rounded arsenal in which his heater rarely cracked 50% usage, to a fastball-heavy repertoire that included his heater more like 60% of the time or more. That meant fewer secondary pitches, and in three games in May the slider even dropped back down to third on the list below the sinker.
I don't know if this alteration was the result of avoiding certain offerings while he pitched through pain, or just a new thing he was trying out, and really the distinction isn't important at this point. It happened, and it didn't work. Hendriks was consistently awful, allowing earned runs in six of his 11 pre-DL games, and multiple runs in five of them.
Since his return, though, the fastball has been creeping back down toward 50% and the secondaries are moving back up, led by the slider. His June was an improvement (2.84 ERA), and his July has been even better as he moved closer to his 2015 game plan (0.87, and a low hit rate). Of course there is ample room for batted ball luck to have skewed some of these splits, but you can definitely start to see a pattern forming based on his pitch selection. It's also not lost on me that his K/BB has declined in the more recent "improved" split, and I don't really have a response to that. If you want more strikeouts, well, his slider is his best whiff pitch so you should be happy he's throwing more of those again.
Finally, what does any of this mean for the future? First, Hendriks has to keep pitching well on a regular basis before we can declare him "back" rather than just "hot." And even then, perhaps he tops out as just an excellent middle reliever, capable of locking down those 6th and 7th innings for you (possibly even both in the same game) but not a great bet for the highest-leverage spots. Having an elite middleman is kind of like having a Pro Bowl punter or a third-string power forward who comes in just to draw a charge or two -- not necessary, but a nice luxury when you have it. And if he does get a shot to set up in the 8th inning and it turns out well, then that's just vegemite on the cake. (I have no idea what you're supposed to put vegemite on.)
Whatever happens, Hendriks is once again becoming a pitcher to watch. And while you watch him, try to notice if he's using his slider.
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