Neither Astorino nor the PSU coaching staff went into detail about the nature of the injury during the season, which hampered him for most of the year and required him to wear a brace that basically held his left arm near his body.
Sources say the operation will likely knock the redshirt junior starter out of action for at least several months, meaning he is doubtful for spring practice. But they added that the medical staff expects him to be back at full strength in time for the season.
Astorino had 62 tackles, two fumble recoveries and an interception in 2009. Of Penn State's top five tacklers, he is the only one returning for 2010.