Boothe was originally drafted by the Raiders, and played in Oakland during the 2006 season before spending the next seven years with the Giants.
He will join former New York teammate Justin Tuck, who signed with the Raiders last week.
It would have been nice to retain Boothe, but the Giants are apparently moving past him. They have JD Walton in the fold and, if healthy, could be the team's center this season. They also have Dallas Reynolds who can serve as the swing center/guard, which was Boothe's role.
The plan could be as many suspect - the Giants will draft a LT, move Will Beatty to RT and shift Justin Pugh to RG if Chris Snee is not 100 percent. Geoff Schwartz will be the LG.