I heard at the boxing hall of fame that he would not touch a pen, but would do a photo. I was not there but that came from a few of my friends who are celebrity autograph hounds.
Collecting Starlin Castro, Brett Jackson, and Ken Griffey Jr. Mariners Inserts
372 Unique Starlin Castro Cards in hand as of 03/24/2013
My Bucket: http://photobucket.com/thechadstarlincastro