The linebacker joined the Giants in 2009, signing a five-year contract, but allowed 550 yards in coverage during the 2012 season.
General manager Jerry Reese told the team's website: "Michael came in and learned our defense quickly and he added speed, coupled with big play ability, to our defensive unit.
"He also played an important role in helping us win Super Bowl XLVI. I wish him well as he moves forward in his career."
The 30-year-old played in every game for the Giants in 2012, starting 11 and recording 84 tackles.