from http://www.giants.com/news/headlines/story.asp?story_id=37843

LB Boley undergoes surgery
By Michael Eisen, Giants.com

JUNE 24, 2009

EAST RUTHERFORD, NJ - The Giants announced on Wednesday that weakside linebacker Michael Boley underwent arthroscopic surgery today to repair a torn labrum in his hip. The surgery was performed by team physician Dr. Bryan Kelly at the Hospital for Special Surgery. A full recovery is expected in approximately 8-10 weeks, the team said. Boley signed with the Giants as a free agent on Feb. 28 after four years with the Atlanta Falcons. Weakside linebacker is the only one of the 22 positions for the Giants to have three starters last season, and all three of those players – Gerris Wilkinson, Bryan Kehl and Chase Blackburn – are still with the team.

So how did he get injured, has that been released yet?

I believe it was minicamp, but I could be wrong