Diagnosing The Source Of Travis Hafner's Slump

Hafner vs OAK

(Syndicated from An A-Blog for A-Rod.  Stats have not been updated to reflect last night's game)

He's managed to fly under the radar for over a month because other players like Vernon Wells and Robinson Cano have been slumping big time too, but Travis Hafner is in a similar production freefall himself.  After last night's 0-fer, he's down to .231/.346/.463 on the season, which is still good for a .350 wOBA that ranks second on the team but a far cry from the high .300s-low .400s value he was holding through his hot start in April.  Hafner missed a handful of games in the middle of April due to a shoulder injury and since he's come back we haven't heard much about any physical problems, yet his production continues to plummet.  What's going on with Pronk that he's become just as much of a black hole in the middle of the lineup as everybody else?  Glad you asked.

His elevated K rates in May (31.2%) and June (29.0%) suggest that Hafner might be getting a little swing happy like Cano and extending his strike zone.  His steady BB rates don't support that theory, however, nor do his swing plots from April and May/June:

Hafner Swing Plot April 2013

Hafner Swing Plot May-June 2013

He's swung at a few more pitches down and out of the zone in the last 6 weeks, but overall Pronk hasn't grossly extended his strike zone to hacker levels.  He's swinging at the same pitches in the same parts of the strike zone that he was when he was hot in April.

So maybe it's the swing itself that is crippling his production.  After an April that was heavy on line drive and flyball contact, Hafner's contact split shifted dramatically in May to a 44.2% GB rate and a 37.2% FB rate.  So far in June he's down to just 11.1% line drives while his FB rate has skyrocketed back above 61.0%.  His BABIP has been incredibly low in both months and these wildly fluctuating contact splits suggest that something is amiss with Hafner's swing, as does his higher whiff rate.

Getting back to his checkered health history, it could also be a case of fatigue or lingering injury that's starting to set in for Hafner too.  We've all been sitting around waiting for that second health-related shoe to drop on him and maybe that's something we should be prepared to find out.  The most likely explanation based on the numbers, though, is a swing problem for Hafner, be it timing or mechanics-related.  Kevin Long made mention of working Cano into his BP group to help him work out of his slump.  It might not be a bad idea to get Pronk into the mix too; see if he can't work a few kinks out.

(Pitch plots courtesy of Texas Leaguers.  Photo courtesy of the AP)