Sanborn was released by the 49ers on Tuesday, Eric Branch of the San Francisco Chronicle reports.
Sanborn joined the 49ers in late September as a retirement fill-in at long snapper, but he's no longer needed with regular long snapper Kyle Nelson returning from suspension.
Sanborn inked a one-year deal with San Francisco on Tuesday.
Sanborn comes in to replace Jon Condo after the latter, via the team's official Twitter account, announced his retirement from the NFL on Monday.
Sanborn signed a contract with the Buccaneers on Tuesday.
Sanborn spent the past eight seasons in Buffalo and did not miss a single game during that run. He'll now take over as the Bills' long snapper for the upcoming season. Details of the contract are still unknown.
The Bills have ruled out wide receivers Marcus Easley (knee) and Marquise Goodwin (hamstring) for their Week 7 battle against the visiting Vikings. Also out is linebacker Ty Powell (ankle).
The team is otherwise healthy - the rest of those on its injury report Friday are probable. They are long snapper Garrison Sanborn (knee), safeties Aaron Williams (wrist/neck) and Da'Norris Searcy (knee), linebacker Brandon Spikes (ribs) and defensive tackle Kyle Williams (knee).
Long snapper Garrison Sanborn finalized a three-year extension with the Buffalo Bills, according to WGR 550 AM Radio in Buffalo. The deal will keep him in Buffalo through 2017.