Ailing Back Hurts Haren’s Velocity, Effectiveness

We’ve seen Dan Haren‘s results this season, and we’ve been wondering what’s going on. His walks are up. He’s giving up more hits. And his FIP is the highest of his career. Granted, his poor first half hasn’t been as alarming as, say, Tim Lincecum’s, but Haren’s been off his game for the first three months of the season.

After Tuesday’s latest disappointing outing, in which he lasted only 4.1 innings, giving up nine hits and six earned runs, Haren revealed that he’s been dealing with a lingering back issue. According to the Orange County Register, “Haren said this year’s problem began when he ‘tweaked’ his back during his final spring training start and has never really gone away.”  [Haren’s last spring training start was on April 2 against the Dodgers. It was a relief to learn that Haren’s back injury arose after the FanGraphs staff saw him at the In-N-Out in Tempe, Arizona on March 11. We were starting to feel a bit responsible.]

Haren will have his back examined by doctors today, now that the Angels have returned from a long road trip. He is scheduled to start on Sunday, but that is very much up in the air. A trip to the disabled list is possible, and would be a first for Haren in his career. He’s pitched more than 215 innings every season dating to 2005, his first full season with the A’s.

An ailing back might explain the noticeable drop in Haren’s velocity. He has four principal pitches: four-seam fastball, split-finger fastball, cutter, and curve ball. According to PITCHf/x, the average speed on his four main pitches is down compared to last season. Haren’s velocity is also down when compared to the average speeds for the same four pitches by American League starters this season.

	Haren 2011 Velocity	Haren 2012 Velocity	Average AL Starter 2012 Velocity
Four-seam	89.8	88.8	91.5
Split-finger	85.5	84.0	84.9
Cutter	85.3	84.6	88.1
Curveball	78.4	76.3	77.4

Okay, so velocity is down. What does that mean?

We don’t know precisely what it means, but the drop in velocity appears to have been made Haren more hittable this season. While his first-pitch-strike rate (65.3) is higher than it was last season (64.6) and higher than his career average (62.4), his swinging-strike rate (9.3) is at the lowest point since 2006 (9.2) and below his career average (9.7).

Indeed, batters are swinging less frequently at Haren’s pitches, particularly those outside the strike zone. His swing rate has dropped from 48.8 to 46.3 last year to this, with the biggest drop coming in swings on pitches outside the strike. His O-Swing rate is down considerably, from 36.2 to 32.3. Not surprisingly, then, Haren’s walk rate has climbed 1.25/9 last season to 2.08/9 this year. On the other hand, when batters are swinging at Haren’s pitches outside the zone, they are making contact at a greater rate (68.0) than at any time in his career.

The results?

Batters are hitting .288 off Haren, the highest of his career. Granted, his BABIP is also at a career high at .329 suggesting some bad luck or defensive inefficiency. Indeed, Haren’s giving up infield hits and bunts for hits at a greater rate than at any time in his career. He’s also, however, yielding more line drives than in any season since his rookie year of 2003. Haren’s also been the victim of the long ball. His fly ball rate (39.6) is up from last year (37.9) and more of those fly balls are leaving the yard. His 12.4 HR/FB is his highest since 2006.

We’re likely to hear news later today or tomorrow on what, exactly, is wrong with Haren’s back and whether he’ll need time on the disabled list. If so, the Angels will be hard pressed to find a replacement starter for Sunday, with Jerome Williams still on the DL with respiratory issues. Indeed, if Haren is out for a while after the All-Star break, the Angels’ rotation depth will be challenged. But better to get Haren fixed and back on track because his reduced velocity has made him more hittable — and less effective — in 2012.