Gonzalez and DeJesus: Arm Injuries Still Not Healed

For the next few weeks, I will be looking at a players who had injuries in 2010 and how they are performing in 2011. I plan on looking at pitchers that came back from Tommy John for next week, but please let me know of any previously injured players you want examined.

Adrian Gonzalez (shoulder): Adrian was one a great acquisitions for the Boston Red Sox this off season. He came in and played 1B thereby allowing Kevin Youkilis to stay in the lineup and play 3B. So far this season, Gonzalez’s production has not been good, especially when looking at his power.

Here are his rate stats over the past 3+ years:

Year	Team	AVG	OBP	SLG
2008	Padres	0.279	0.361	0.510
2009	Padres	0.277	0.407	0.551
2010	Padres	0.298	0.393	0.511
2011	Red Sox	0.310	0.371	0.451

All the stats look fairly similar expect his SLG which is down 60 points. His home runs are especially down since he has hit a total of 1 this year. If he was to get approximately the same number PAs and home runs in the next 5 months, he would end up with a total 7 home runs. He was able to average 35 home runs in past 3 season with half his games in spacious PETCO.

Two real and one false reasons stick out as the reason for the power drop off.

First, he is hitting ~6% more ground balls this season compared to his career average. He needs to be driving the ball or putting it into the air to have the most value.

Second and more important, he is not getting many fly balls to go for home runs. Historically 16.7% of all of his fly balls have gone for home runs. This season, only 2.9% of his fly balls have gone for home runs. One possible reason for the decline is that he is not hitting the ball as far as in previous seasons. Here is a graph of his fly ball distances (ft) over the past 3 seasons:

This season he is hitting the ball an average of 20 ft less than just two years ago. His shoulder may have been acting up last season (the reason behind the surgery this off season) and that is why his 2010 numbers were down a bit also.

One other possible reason people may point to for Adrian’s drop off is a possible lack of plate discipline as seen by a walk rate that is down over 5% this season (13.4% to 8.1%). When looking at anyone’s walk rate, remember to take into account IBB. Adrian had no protection in San Diego, so he got intentionally walked quite a bit. He has only 2 IBB this season vice last season when he had 35. Removing IBB from the walk rate equations, his walk rate drops only 2.2% (8.8% to 6.6%)

David DeJesus – (right thumb injury) – After being traded to Oakland this off season from Kansas City, people expected his stats to drop some because he will be playing half his games in spacious Oakland coliseum. David’s stats have done more than drop a bit, they are free falling.

Zips projected him to have a slash line of 0.264/0.329/0.360 for this season. David is currently at 0.226/0.305/0.0.258 with 0 home runs. It is not a good season when your current SLG is below where your batting average should be. His ISO values are ~1/4 of what it has been over the past 3 years:

2007 0.145
2008 0.152
2009 0.125
2010 0.032

David is just not able to put much power behind his hits this season.

This decrease in power can futher be seen in his batted ball data. From 2010 to 2011, David’s LD% is down from 20.9% to 17.3% and his OFFB% is down from 26.0% to 18.6%. The fly balls that are even making it to the OF are not traveling as far as seen in this batted ball distance profile where he has not hit a fly ball over 350 feet yet:

David is not producing to his normal standards. His hand injury may still be affecting his swing, but only he knows for sure.