During the baseball off-season, players have a chance to do so many activities.  Some of this includes charity fundraisers, workout programs, and constructing bunk-beds.  But there is one activity that fantasy owners should always try to keep an eye on, and that’s a player’s medical visits.  Here is an interesting tidbit many in your league may not know as they head into the fantasy draft room this upcoming season: Chase Headley underwent arthroscopic surgery for his left knee on October 1^st, 2013.  He is expected to be ready for spring training, but this news isn’t the point of my, well,…point.

The crux of this news is that Headley’s surgery can provide some explanation as to why he had such a disappointing 2013 fantasy season.  Now, some may want to blame the thumb injury that occurred during the spring, while others will simply chalk up his 2012 success as a fluke, and both could be seen as logical reasons.  But it looks like the true culprit may have been the third baseman’s left knee.  As I approached this possibility, I thought of the piece I wrote about Headley on June 10^th of last season, trying to figure out where he was headed (hence its clever title) for the rest of the year.  This is an excerpt from the article as I attempted to study the switch-hitter’s swing from the left-side:

“The only possible difference I see in the two swings are Headley’s legs.  In the 2012 video, his front leg fully extends on contact.  The back leg seems steady and balanced.  In 2013, the front leg does not fully extend until shortly after contact, and the back leg may have a little less balance to it.  I didn’t watch all of his home runs, but this seems to be consistent from the videos I did watch.  This could just be a timing issue or a mechanical issue.”

As it turns out, Headley was playing through a left knee injury all of last season, as he injured it during spring training.  So, what I noticed was likely real.  However, the question remains, did the unhealthy knee really affect his swing? 

Headley’s back leg, in this case, the left, is responsible for taking on, as well as shifting weight, all the while keeping the body balanced.  If the knee is compromised, it is reasonable to assume that it would affect his base, and therefore his swing, which could also mean his power.  I imagine there is some level of pain involved with every swing too.  Headley’s splits during 2013 add more to the story.  From the right-side, with a healthy back leg, he hit five home runs in 150 at-bats with an ISO of .188 and a SLG% of .436, both better than his career marks.  From the left-side, on an injured back leg, he hit eight homers in 371 at-bats with an ISO of .136 and a SLG% OF .386, both worse than his career marks.  In 2012, he generated much more power as a lefty, hitting 20 dingers in 413 at-bats with an ISO of .213 and a SLG% of .513, beating out his production as a righty. 

The videos from my prior piece of Headley’s swings show a subtle difference, but I do believe it exists.  Below are the GIF versions.  I viewed many of his swings to form this opinion, so if you would like, you can view more on MLB.com or elsewhere.

Headley made real changes in 2012.  And he did have power in the minors.  A quick Google search reveals even more information about the slugger’s transformation.  So, should we really write-off a guy who will likely come at a nice discount in upcoming drafts? 

Headley’s 2013 numbers fall in line nicely with his 2012 breakout campaign, with the exception of his HR/FB percentage, which is the biggest query, isn’t it?  During his breakout, he had a 21.4 HR/FB%, only for it to fall to 10.9% in 2013.  And although no one expected the switch-hitter to sustain that rate, there are enough reasons to believe he could deliver better than 10.9%.  Below are three spray charts from 2011, 2012, and 2013, all showing where Headley put his balls in play batting as a left-handed hitter.

There is a clear difference between Headley’s 2011 and the following two seasons.  He decided to pull the ball more.  Again, we already knew this, but the truth remains that his 2013 looks more like his 2012, than it does his 2011. 

So to answer the question, Headley’s power was real in 2012, at least, somewhat.  Will he ever hit 30 homers again?  I would lean towards no, but that doesn’t mean he can’t hit 20, or close in on 25 bombs.  The change in approach is real.  The knee injury, the thumb injury, these look like factors that affected his power.  Even his work on the base paths tells a similar tale.  Headley was a solid source in the stolen base department the past several seasons, usually providing steals in the mid-teens and hovering around 20 or so attempts.  Last season, he only stole eight bases on 12 tries.  He did miss some time, but that didn’t stop him in 2011 when he stole 13 bases in 113 games.

When we look back on Headley’s 2013 season, the injuries could reasonably explain his fantasy shortcomings.  This gives us a real reason to buy low for a nice payoff.  Considering his potential for double digit steals and 20 homers at third-base, you shouldn’t forget about the 29-year-old.  A 15-15 season can even be valuable in deeper leagues, so when draft day comes, don’t let Chase Headley slip too far.

Thanks to Fangraphs.com and Brooksbaseball.net for the data.