Mark DeRosa’s Wrist Injury Continues to Sap Power:

Mark DeRosa has gotten off to a lousy start to say the least. He is struggling to hit the ball with any authority which has lead to a poor batting average and even worse power numbers.

The only saving grace at this point is that he continues to take a walk. He has manages to walk in around 10% of his plate appearences which has kept his on base percentage about 100 points higher then his batting average. Below is a look at his numbers this season compared to his career averages. There has been a substantial drop off in production

Year	BA	OBP	SLG	OPS	ISO
2010	.190	.289	.253	.542	.063
13 Seasons	.273	.342	.420	.761	.147

Provided by Baseball-Reference.com: View Original Table

Generated 5/6/2010.

This makes you have to wonder if his wrist is still bugging him and what has lead to his struggles this season. DeRosa says that there is not any pain but he still has weakness in the wrist he hurt last July and had surgery to repair it in the offseason and by looking at his numbers and where he has driven the ball it appears that he is still not back to 100%.

It seems that even DeRosa might be having the same concerns as reported by Andrew Baggarly of the Bay Area News group.

"I'll get a fastball that (in the past) I'd hit to left-center field for a double, and instead I'm grounding out to third base. I'm going down the line thinking, `What the hell are you doing? What's going on?'

In previous years before the injury DeRosa hit the ball to all fields with a good portion of his power to left field. Below is his spray chart from before the injury. (Note: It is overlaid on AT&T Park but this is for all fields, spray chart from texas leaguers which has tons of great info)

This season he has lacked being able to drive the ball to his pull field at all with only 2 balls into left field both of which were hit on the ground through the third base shortstop whole. The balls hit into the out field have all gone to center or right field with only 2 that were hit relatively deep. (Note: It is overlaid on AT&T Park but this is for all fields, spray chart from texas leaguers which has tons of great info)

This trend should be some cause for concern; at the very least perhaps Bruce Bochy should move him down in the lineup or consider giving him some more rest until he starts to show the ability to hit the ball hard to all fields. With the Giants working to make the playoffs they cannot afford to have another weak bat in the lineup if they can avoid it.

Beyond the Box score had a nice peice that shows that there does seem to be some relationship between wrist injuries and a loss of power during the recovery period which usually takes about a year to fully heal. If that is the case we may have a long season of struggles from our big leftfield acquisition.